diff --git a/.github/actions/install-wasi-sdk/action.yml b/.github/actions/install-wasi-sdk/action.yml
index 169f68c93..5b0798a59 100644
--- a/.github/actions/install-wasi-sdk/action.yml
+++ b/.github/actions/install-wasi-sdk/action.yml
@@ -34,8 +34,8 @@ runs:
     - name: Setup `wasm-tools`
       uses: bytecodealliance/actions/wasm-tools/setup@v1
       with:
-        version: "1.247.0"
+        version: "1.252.0"
     - name: Setup `wasmtime`
       uses: bytecodealliance/actions/wasmtime/setup@v1
       with:
-        version: "44.0.0"
+        version: "46.0.1"
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index c22eee340..3a86dcb49 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -104,11 +104,22 @@ jobs:
         dotnet-version: '9.x'
       if: matrix.lang == 'csharp'
 
+    # As of this writing async tests require [a patched build of
+    # Go](https://github.com/dicej/go/releases/tag/go1.25.5-wasi-on-idle).
+    # Install this on Linux to get coverage, but don't install it on
+    # macOS/Windows to also get coverage for test-without-a-patched-toolchain.
+    - name: Install Patched Go
+      run: |
+        curl -OL https://github.com/dicej/go/releases/download/go1.25.5-wasi-on-idle/go-linux-amd64-bootstrap.tbz
+        tar xf go-linux-amd64-bootstrap.tbz
+        echo "$(pwd)/go-linux-amd64-bootstrap/bin" >> $GITHUB_PATH
+      if: matrix.lang == 'go' && matrix.os == 'ubuntu-latest'
+
     - name: Setup Go
       uses: actions/setup-go@v5
       with:
         go-version: 1.25.4
-      if: matrix.lang == 'go'
+      if: matrix.lang == 'go' && matrix.os != 'ubuntu-latest'
 
       # Hacky work-around for https://github.com/dotnet/runtime/issues/80619
     - run: dotnet new console -o /tmp/foo
@@ -130,17 +141,17 @@ jobs:
           --artifacts target/artifacts \
           --rust-wit-bindgen-path ./crates/guest-rust
 
-    # Run all runtime tests for this language, and also enable Rust in case this
-    # language only implements either the runner or test component
+    # Run all runtime tests for this language, and also enable Rust & C in case
+    # this language only implements either the runner or test component
     - run: |
-        cargo run test --languages rust,${{ matrix.lang }} tests/runtime \
+        cargo run test --languages rust,c,${{ matrix.lang }} tests/runtime \
           --artifacts target/artifacts \
           --rust-wit-bindgen-path ./crates/guest-rust
 
-  # While async is off-by-default and toolchains are percolating this is a
+  # While threading is off-by-default and toolchains are percolating this is a
   # separate job to get configured slightly differently.
-  async:
-    name: Test Async (allowed to fail)
+  threading:
+    name: Test WASIp3 Threading (allowed to fail)
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
@@ -151,18 +162,9 @@ jobs:
       run: rustup update stable --no-self-update && rustup default stable
     - run: rustup target add wasm32-wasip2
 
-    # As of this writing, we need [a patched build of
-    # Go](https://github.com/dicej/go/releases/tag/go1.25.5-wasi-on-idle) to
-    # support async.
-    - name: Install Patched Go
-      run: |
-        curl -OL https://github.com/dicej/go/releases/download/go1.25.5-wasi-on-idle/go-linux-amd64-bootstrap.tbz
-        tar xf go-linux-amd64-bootstrap.tbz
-        echo "$(pwd)/go-linux-amd64-bootstrap/bin" >> $GITHUB_PATH
-
     - uses: ./.github/actions/install-wasi-sdk
     - run: |
-        cargo run test --languages rust,c,go tests/runtime-async \
+        cargo run test --languages rust,c,go tests/threading \
           --artifacts target/artifacts \
           --rust-wit-bindgen-path ./crates/guest-rust
 
@@ -287,7 +289,6 @@ jobs:
       - verify-publish
       - check
       - msrv
-      # - async
     if: always()
 
     steps:
diff --git a/Cargo.lock b/Cargo.lock
index 2e6530677..63a642d15 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1215,9 +1215,9 @@ dependencies = [
 
 [[package]]
 name = "wasi-preview1-component-adapter-provider"
-version = "45.0.1"
+version = "46.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02ed52111afc004605074d1a3fad77ba3ac85c0c0b8ad028919275a46fec8cfd"
+checksum = "1b6c48003fe59c201c97a7786ff55feabe6b6f83b598aa9ff5bcc4f94d940bf3"
 
 [[package]]
 name = "wasm-compose"
diff --git a/crates/test/Cargo.toml b/crates/test/Cargo.toml
index 4100f71a5..14c80e0d9 100644
--- a/crates/test/Cargo.toml
+++ b/crates/test/Cargo.toml
@@ -26,7 +26,7 @@ log = "0.4.26"
 regex = "1.11.1"
 serde = { workspace = true }
 toml = "1.1.2"
-wasi-preview1-component-adapter-provider = "45.0.1"
+wasi-preview1-component-adapter-provider = "46.0.1"
 wac-parser = "0.10.0"
 wac-types = "0.10.0"
 wac-graph = "0.10.0"
diff --git a/crates/test/src/c.rs b/crates/test/src/c.rs
index a34f2fc55..a04dbf967 100644
--- a/crates/test/src/c.rs
+++ b/crates/test/src/c.rs
@@ -52,6 +52,7 @@ impl LanguageMethods for C {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         name: &str,
         config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/crates/test/src/cpp.rs b/crates/test/src/cpp.rs
index bf49ad3a8..d33cefa11 100644
--- a/crates/test/src/cpp.rs
+++ b/crates/test/src/cpp.rs
@@ -41,6 +41,7 @@ impl LanguageMethods for Cpp {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         name: &str,
         config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/crates/test/src/csharp.rs b/crates/test/src/csharp.rs
index 8e11ca7f7..6327ca029 100644
--- a/crates/test/src/csharp.rs
+++ b/crates/test/src/csharp.rs
@@ -36,6 +36,7 @@ impl LanguageMethods for Csharp {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         name: &str,
         _config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/crates/test/src/custom.rs b/crates/test/src/custom.rs
index 402fe65f4..8a56032d9 100644
--- a/crates/test/src/custom.rs
+++ b/crates/test/src/custom.rs
@@ -101,6 +101,7 @@ impl LanguageMethods for Language {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         _name: &str,
         _config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/crates/test/src/go.rs b/crates/test/src/go.rs
index afe651951..7655b26df 100644
--- a/crates/test/src/go.rs
+++ b/crates/test/src/go.rs
@@ -7,6 +7,22 @@ use std::process::Command;
 
 pub struct Go;
 
+/// Go-specific state, stored in `Runner`, detected during `prepare`.
+pub struct State {
+    /// Whether the Go toolchain in use supports the `runtime.wasiOnIdle` hook
+    /// required for component model async support.
+    async_supported: bool,
+}
+
+impl Runner {
+    fn go_async_supported(&self) -> bool {
+        self.go_state
+            .as_ref()
+            .map(|s| s.async_supported)
+            .unwrap_or(false)
+    }
+}
+
 impl LanguageMethods for Go {
     fn display(&self) -> &str {
         "go"
@@ -18,19 +34,43 @@ impl LanguageMethods for Go {
 
     fn should_fail_verify(
         &self,
+        runner: &Runner,
         name: &str,
         config: &crate::config::WitConfig,
         _args: &[String],
     ) -> bool {
-        // TODO: We _do_ support async, but only with a build of Go that has
-        // [this
-        // patch](https://github.com/dicej/go/commit/40fc123d5bce6448fc4e4601fd33bad4250b36a5).
-        // Once we upstream something equivalent, we can remove the ` || name ==
-        // "async-trait-function.wit"` here.
-        config.error_context
-            || name == "async-trait-function.wit"
-            || name == "named-fixed-length-list.wit"
-            || name == "issue-1598.wit"
+        if config.error_context {
+            return true;
+        }
+        if name == "named-fixed-length-list.wit" {
+            return true;
+        }
+        if !runner.go_async_supported() {
+            return name == "async-trait-function.wit" || name == "issue-1598.wit";
+        }
+
+        false
+    }
+
+    fn should_fail_compile(
+        &self,
+        runner: &Runner,
+        path: &Path,
+        config: &crate::config::WitConfig,
+    ) -> bool {
+        // This test, even though it's part of async, compiles on any
+        // toolchain.
+        if path.ends_with("incomplete-writes/leaf.go") {
+            return false;
+        }
+
+        // Bindings for async tests rely on `runtime.wasiOnIdle` (see `prepare`
+        // below) and fail to link without a toolchain that provides it.
+        if !runner.go_async_supported() {
+            return config.async_;
+        }
+
+        false
     }
 
     fn default_bindgen_args_for_codegen(&self) -> &[&str] {
@@ -56,7 +96,45 @@ impl LanguageMethods for Go {
                 .arg("build")
                 .arg("-buildmode=c-shared")
                 .arg("-ldflags=-checklinkname=0"),
-        )
+        )?;
+
+        // Component model async support requires a `runtime.wasiOnIdle` hook
+        // which, as of the time of this writing, is only available in a
+        // patched build of Go. Detect whether the toolchain in use has
+        // this hook by building a program that links against it, and if not
+        // then async tests are expected to fail to build.
+        println!("Testing if `go` supports `runtime.wasiOnIdle`...");
+        let probe_dir = dir.join("wasi-on-idle-probe");
+        super::write_if_different(
+            &probe_dir.join("main.go"),
+            r#"package main
+
+import _ "unsafe"
+
+//go:linkname wasiOnIdle runtime.wasiOnIdle
+func wasiOnIdle(callback func() bool)
+func init() { defer wasiOnIdle(func() bool { return false }) }
+func main() {}
+"#,
+        )?;
+        super::write_if_different(&probe_dir.join("go.mod"), "module probe\n\ngo 1.25")?;
+        let async_supported = runner
+            .run_command(
+                Command::new("go")
+                    .current_dir(&probe_dir)
+                    .env("GOOS", "wasip1")
+                    .env("GOARCH", "wasm")
+                    .arg("build")
+                    .arg("-o")
+                    .arg("probe.wasm")
+                    .arg("-buildmode=c-shared")
+                    .arg("-ldflags=-checklinkname=0"),
+            )
+            .is_ok();
+        println!("`runtime.wasiOnIdle` supported: {async_supported}");
+        runner.go_state = Some(State { async_supported });
+
+        Ok(())
     }
 
     fn compile(&self, runner: &Runner, compile: &Compile<'_>) -> Result<()> {
diff --git a/crates/test/src/lib.rs b/crates/test/src/lib.rs
index 615fb9ce0..7a54f4612 100644
--- a/crates/test/src/lib.rs
+++ b/crates/test/src/lib.rs
@@ -137,6 +137,7 @@ impl Opts {
         Runner {
             opts: self.clone(),
             rust_state: None,
+            go_state: None,
             wit_bindgen: wit_bindgen.to_path_buf(),
             test_runner: runner::TestRunner::new(&self.runner)?,
         }
@@ -254,6 +255,7 @@ struct Verify<'a> {
 struct Runner {
     opts: Opts,
     rust_state: Option<rust::State>,
+    go_state: Option<go::State>,
     wit_bindgen: PathBuf,
     test_runner: runner::TestRunner,
 }
@@ -578,7 +580,7 @@ impl Runner {
                     let me = self.clone();
                     let should_fail = language
                         .obj()
-                        .should_fail_verify(&args_kind, &config, &args);
+                        .should_fail_verify(self, &args_kind, &config, &args);
 
                     let name = format!("{language} {args_kind} {test:?}");
                     Trial::test(&name, move || {
@@ -703,17 +705,23 @@ impl Runner {
                     let compilations = compilations.clone();
                     let test = test.clone();
                     let component = component.clone();
+                    let should_fail = component.language.obj().should_fail_compile(
+                        self,
+                        &component.path,
+                        &component.bindgen.wit_config,
+                    );
                     Trial::test(&component.path.display().to_string(), move || {
                         let result = me.compile_component(&test, &component).with_context(|| {
                             format!("failed to compile component {:?}", component.path)
                         });
                         match result {
-                            Ok(path) => {
+                            Ok(path) if !should_fail => {
                                 compilations.lock().unwrap().push((test, component, path));
                                 Ok(())
                             }
-                            Err(e) => me.render_error(
-                                StepResult::new(Err(e))
+                            other => me.render_error(
+                                StepResult::new(other.map(|_| ()))
+                                    .should_fail(should_fail)
                                     .metadata("component", &component.name)
                                     .metadata("path", component.path.display()),
                             ),
@@ -1280,7 +1288,25 @@ trait LanguageMethods {
 
     /// Returns whether this language is supposed to fail this codegen tests
     /// given the `config` and `args` for the test.
-    fn should_fail_verify(&self, name: &str, config: &config::WitConfig, args: &[String]) -> bool;
+    fn should_fail_verify(
+        &self,
+        runner: &Runner,
+        name: &str,
+        config: &config::WitConfig,
+        args: &[String],
+    ) -> bool;
+
+    /// Returns whether this language is expected to fail to compile the
+    /// runtime test component described by `config`.
+    fn should_fail_compile(
+        &self,
+        runner: &Runner,
+        path: &Path,
+        config: &config::WitConfig,
+    ) -> bool {
+        let _ = (runner, path, config);
+        false
+    }
 
     /// Performs a "check" or a verify that the generated bindings described by
     /// `Verify` are indeed valid.
diff --git a/crates/test/src/moonbit.rs b/crates/test/src/moonbit.rs
index a837ae93e..8811314f5 100644
--- a/crates/test/src/moonbit.rs
+++ b/crates/test/src/moonbit.rs
@@ -120,6 +120,7 @@ impl LanguageMethods for MoonBit {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         name: &str,
         config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/crates/test/src/rust.rs b/crates/test/src/rust.rs
index fe492d60e..53484c29c 100644
--- a/crates/test/src/rust.rs
+++ b/crates/test/src/rust.rs
@@ -56,6 +56,7 @@ impl LanguageMethods for Rust {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         name: &str,
         _config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/crates/test/src/wat.rs b/crates/test/src/wat.rs
index 1cd59cdce..8278ade8e 100644
--- a/crates/test/src/wat.rs
+++ b/crates/test/src/wat.rs
@@ -14,6 +14,7 @@ impl LanguageMethods for Wat {
 
     fn should_fail_verify(
         &self,
+        _runner: &Runner,
         _name: &str,
         _config: &crate::config::WitConfig,
         _args: &[String],
diff --git a/tests/runtime-async/async/cancel-import/runner.c b/tests/runtime/cancel-import/runner.c
similarity index 100%
rename from tests/runtime-async/async/cancel-import/runner.c
rename to tests/runtime/cancel-import/runner.c
diff --git a/tests/runtime-async/async/cancel-import/runner.rs b/tests/runtime/cancel-import/runner.rs
similarity index 100%
rename from tests/runtime-async/async/cancel-import/runner.rs
rename to tests/runtime/cancel-import/runner.rs
diff --git a/tests/runtime-async/async/cancel-import/test.c b/tests/runtime/cancel-import/test.c
similarity index 100%
rename from tests/runtime-async/async/cancel-import/test.c
rename to tests/runtime/cancel-import/test.c
diff --git a/tests/runtime-async/async/cancel-import/test.rs b/tests/runtime/cancel-import/test.rs
similarity index 100%
rename from tests/runtime-async/async/cancel-import/test.rs
rename to tests/runtime/cancel-import/test.rs
diff --git a/tests/runtime-async/async/cancel-import/test.wit b/tests/runtime/cancel-import/test.wit
similarity index 92%
rename from tests/runtime-async/async/cancel-import/test.wit
rename to tests/runtime/cancel-import/test.wit
index 78e57ec13..66a8c365e 100644
--- a/tests/runtime-async/async/cancel-import/test.wit
+++ b/tests/runtime/cancel-import/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/future-cancel-read/runner.cs b/tests/runtime/future-cancel-read/disabled/runner.cs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/runner.cs
rename to tests/runtime/future-cancel-read/disabled/runner.cs
diff --git a/tests/runtime-async/async/future-cancel-read/test.cs b/tests/runtime/future-cancel-read/disabled/test.cs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/test.cs
rename to tests/runtime/future-cancel-read/disabled/test.cs
diff --git a/tests/runtime-async/async/future-cancel-read/runner.c b/tests/runtime/future-cancel-read/runner.c
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/runner.c
rename to tests/runtime/future-cancel-read/runner.c
diff --git a/tests/runtime-async/async/future-cancel-read/runner.rs b/tests/runtime/future-cancel-read/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/runner.rs
rename to tests/runtime/future-cancel-read/runner.rs
diff --git a/tests/runtime-async/async/future-cancel-read/test.c b/tests/runtime/future-cancel-read/test.c
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/test.c
rename to tests/runtime/future-cancel-read/test.c
diff --git a/tests/runtime-async/async/future-cancel-read/test.mbt b/tests/runtime/future-cancel-read/test.mbt
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/test.mbt
rename to tests/runtime/future-cancel-read/test.mbt
diff --git a/tests/runtime-async/async/future-cancel-read/test.rs b/tests/runtime/future-cancel-read/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-read/test.rs
rename to tests/runtime/future-cancel-read/test.rs
diff --git a/tests/runtime-async/async/future-cancel-read/test.wit b/tests/runtime/future-cancel-read/test.wit
similarity index 94%
rename from tests/runtime-async/async/future-cancel-read/test.wit
rename to tests/runtime/future-cancel-read/test.wit
index 52bbcd51c..df8e3e30c 100644
--- a/tests/runtime-async/async/future-cancel-read/test.wit
+++ b/tests/runtime/future-cancel-read/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/future-cancel-write-then-read/runner.rs b/tests/runtime/future-cancel-write-then-read/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write-then-read/runner.rs
rename to tests/runtime/future-cancel-write-then-read/runner.rs
diff --git a/tests/runtime-async/async/future-cancel-write-then-read/test.rs b/tests/runtime/future-cancel-write-then-read/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write-then-read/test.rs
rename to tests/runtime/future-cancel-write-then-read/test.rs
diff --git a/tests/runtime-async/async/future-cancel-write-then-read/test.wit b/tests/runtime/future-cancel-write-then-read/test.wit
similarity index 91%
rename from tests/runtime-async/async/future-cancel-write-then-read/test.wit
rename to tests/runtime/future-cancel-write-then-read/test.wit
index 1995d936a..78780f2db 100644
--- a/tests/runtime-async/async/future-cancel-write-then-read/test.wit
+++ b/tests/runtime/future-cancel-write-then-read/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface the-test {
diff --git a/tests/runtime-async/async/future-cancel-write/runner.c b/tests/runtime/future-cancel-write/runner.c
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write/runner.c
rename to tests/runtime/future-cancel-write/runner.c
diff --git a/tests/runtime-async/async/future-cancel-write/runner.rs b/tests/runtime/future-cancel-write/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write/runner.rs
rename to tests/runtime/future-cancel-write/runner.rs
diff --git a/tests/runtime-async/async/future-cancel-write/test.c b/tests/runtime/future-cancel-write/test.c
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write/test.c
rename to tests/runtime/future-cancel-write/test.c
diff --git a/tests/runtime-async/async/future-cancel-write/test.mbt b/tests/runtime/future-cancel-write/test.mbt
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write/test.mbt
rename to tests/runtime/future-cancel-write/test.mbt
diff --git a/tests/runtime-async/async/future-cancel-write/test.rs b/tests/runtime/future-cancel-write/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-cancel-write/test.rs
rename to tests/runtime/future-cancel-write/test.rs
diff --git a/tests/runtime-async/async/future-cancel-write/test.wit b/tests/runtime/future-cancel-write/test.wit
similarity index 92%
rename from tests/runtime-async/async/future-cancel-write/test.wit
rename to tests/runtime/future-cancel-write/test.wit
index 3b4dc207a..4d71ca6b9 100644
--- a/tests/runtime-async/async/future-cancel-write/test.wit
+++ b/tests/runtime/future-cancel-write/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/future-close-after-coming-back/runner.rs b/tests/runtime/future-close-after-coming-back/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-close-after-coming-back/runner.rs
rename to tests/runtime/future-close-after-coming-back/runner.rs
diff --git a/tests/runtime-async/async/future-close-after-coming-back/test.mbt b/tests/runtime/future-close-after-coming-back/test.mbt
similarity index 100%
rename from tests/runtime-async/async/future-close-after-coming-back/test.mbt
rename to tests/runtime/future-close-after-coming-back/test.mbt
diff --git a/tests/runtime-async/async/future-close-after-coming-back/test.rs b/tests/runtime/future-close-after-coming-back/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-close-after-coming-back/test.rs
rename to tests/runtime/future-close-after-coming-back/test.rs
diff --git a/tests/runtime-async/async/future-write-then-read-comes-back/test.wit b/tests/runtime/future-close-after-coming-back/test.wit
similarity index 91%
rename from tests/runtime-async/async/future-write-then-read-comes-back/test.wit
rename to tests/runtime/future-close-after-coming-back/test.wit
index 12083a297..fb7865ef6 100644
--- a/tests/runtime-async/async/future-write-then-read-comes-back/test.wit
+++ b/tests/runtime/future-close-after-coming-back/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface the-test {
diff --git a/tests/runtime-async/async/future-close-then-receive-read/runner.rs b/tests/runtime/future-close-then-receive-read/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-close-then-receive-read/runner.rs
rename to tests/runtime/future-close-then-receive-read/runner.rs
diff --git a/tests/runtime-async/async/future-close-then-receive-read/test.rs b/tests/runtime/future-close-then-receive-read/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-close-then-receive-read/test.rs
rename to tests/runtime/future-close-then-receive-read/test.rs
diff --git a/tests/runtime-async/async/future-close-then-receive-read/test.wit b/tests/runtime/future-close-then-receive-read/test.wit
similarity index 91%
rename from tests/runtime-async/async/future-close-then-receive-read/test.wit
rename to tests/runtime/future-close-then-receive-read/test.wit
index cc7f391e1..ec970d290 100644
--- a/tests/runtime-async/async/future-close-then-receive-read/test.wit
+++ b/tests/runtime/future-close-then-receive-read/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface the-test {
diff --git a/tests/runtime-async/async/future-closes-with-error/runner.rs b/tests/runtime/future-closes-with-error/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-closes-with-error/runner.rs
rename to tests/runtime/future-closes-with-error/runner.rs
diff --git a/tests/runtime-async/async/future-closes-with-error/test.rs b/tests/runtime/future-closes-with-error/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-closes-with-error/test.rs
rename to tests/runtime/future-closes-with-error/test.rs
diff --git a/tests/runtime-async/async/future-closes-with-error/test.wit b/tests/runtime/future-closes-with-error/test.wit
similarity index 90%
rename from tests/runtime-async/async/future-closes-with-error/test.wit
rename to tests/runtime/future-closes-with-error/test.wit
index 58211d988..634fcae53 100644
--- a/tests/runtime-async/async/future-closes-with-error/test.wit
+++ b/tests/runtime/future-closes-with-error/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface the-test {
diff --git a/tests/runtime-async/async/future-write-then-read-comes-back/runner.rs b/tests/runtime/future-write-then-read-comes-back/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-write-then-read-comes-back/runner.rs
rename to tests/runtime/future-write-then-read-comes-back/runner.rs
diff --git a/tests/runtime-async/async/future-write-then-read-comes-back/test.rs b/tests/runtime/future-write-then-read-comes-back/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-write-then-read-comes-back/test.rs
rename to tests/runtime/future-write-then-read-comes-back/test.rs
diff --git a/tests/runtime-async/async/future-close-after-coming-back/test.wit b/tests/runtime/future-write-then-read-comes-back/test.wit
similarity index 91%
rename from tests/runtime-async/async/future-close-after-coming-back/test.wit
rename to tests/runtime/future-write-then-read-comes-back/test.wit
index 12083a297..fb7865ef6 100644
--- a/tests/runtime-async/async/future-close-after-coming-back/test.wit
+++ b/tests/runtime/future-write-then-read-comes-back/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface the-test {
diff --git a/tests/runtime-async/async/future-write-then-read-remote/runner.rs b/tests/runtime/future-write-then-read-remote/runner.rs
similarity index 100%
rename from tests/runtime-async/async/future-write-then-read-remote/runner.rs
rename to tests/runtime/future-write-then-read-remote/runner.rs
diff --git a/tests/runtime-async/async/future-write-then-read-remote/runner2.rs b/tests/runtime/future-write-then-read-remote/runner2.rs
similarity index 100%
rename from tests/runtime-async/async/future-write-then-read-remote/runner2.rs
rename to tests/runtime/future-write-then-read-remote/runner2.rs
diff --git a/tests/runtime-async/async/future-write-then-read-remote/test.rs b/tests/runtime/future-write-then-read-remote/test.rs
similarity index 100%
rename from tests/runtime-async/async/future-write-then-read-remote/test.rs
rename to tests/runtime/future-write-then-read-remote/test.rs
diff --git a/tests/runtime-async/async/future-write-then-read-remote/test.wit b/tests/runtime/future-write-then-read-remote/test.wit
similarity index 90%
rename from tests/runtime-async/async/future-write-then-read-remote/test.wit
rename to tests/runtime/future-write-then-read-remote/test.wit
index 58211d988..634fcae53 100644
--- a/tests/runtime-async/async/future-write-then-read-remote/test.wit
+++ b/tests/runtime/future-write-then-read-remote/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface the-test {
diff --git a/tests/runtime-async/async/incomplete-writes/leaf.go b/tests/runtime/incomplete-writes/leaf.go
similarity index 100%
rename from tests/runtime-async/async/incomplete-writes/leaf.go
rename to tests/runtime/incomplete-writes/leaf.go
diff --git a/tests/runtime-async/async/incomplete-writes/runner.go b/tests/runtime/incomplete-writes/runner.go
similarity index 100%
rename from tests/runtime-async/async/incomplete-writes/runner.go
rename to tests/runtime/incomplete-writes/runner.go
diff --git a/tests/runtime-async/async/incomplete-writes/test.go b/tests/runtime/incomplete-writes/test.go
similarity index 100%
rename from tests/runtime-async/async/incomplete-writes/test.go
rename to tests/runtime/incomplete-writes/test.go
diff --git a/tests/runtime-async/async/incomplete-writes/test.wit b/tests/runtime/incomplete-writes/test.wit
similarity index 98%
rename from tests/runtime-async/async/incomplete-writes/test.wit
rename to tests/runtime/incomplete-writes/test.wit
index 6e3604133..6498e3a90 100644
--- a/tests/runtime-async/async/incomplete-writes/test.wit
+++ b/tests/runtime/incomplete-writes/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 //@ dependencies = ['test', 'leaf']
 
 package my:test;
diff --git a/tests/runtime-async/async/pending-import/runner.c b/tests/runtime/pending-import/runner.c
similarity index 100%
rename from tests/runtime-async/async/pending-import/runner.c
rename to tests/runtime/pending-import/runner.c
diff --git a/tests/runtime-async/async/pending-import/runner.cs b/tests/runtime/pending-import/runner.cs
similarity index 100%
rename from tests/runtime-async/async/pending-import/runner.cs
rename to tests/runtime/pending-import/runner.cs
diff --git a/tests/runtime-async/async/pending-import/runner.rs b/tests/runtime/pending-import/runner.rs
similarity index 100%
rename from tests/runtime-async/async/pending-import/runner.rs
rename to tests/runtime/pending-import/runner.rs
diff --git a/tests/runtime-async/async/pending-import/test.c b/tests/runtime/pending-import/test.c
similarity index 100%
rename from tests/runtime-async/async/pending-import/test.c
rename to tests/runtime/pending-import/test.c
diff --git a/tests/runtime-async/async/pending-import/test.cs b/tests/runtime/pending-import/test.cs
similarity index 100%
rename from tests/runtime-async/async/pending-import/test.cs
rename to tests/runtime/pending-import/test.cs
diff --git a/tests/runtime-async/async/pending-import/test.rs b/tests/runtime/pending-import/test.rs
similarity index 100%
rename from tests/runtime-async/async/pending-import/test.rs
rename to tests/runtime/pending-import/test.rs
diff --git a/tests/runtime-async/async/pending-import/test.wit b/tests/runtime/pending-import/test.wit
similarity index 90%
rename from tests/runtime-async/async/pending-import/test.wit
rename to tests/runtime/pending-import/test.wit
index a5ab30cda..0a586a2d3 100644
--- a/tests/runtime-async/async/pending-import/test.wit
+++ b/tests/runtime/pending-import/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/ping-pong/runner.cs b/tests/runtime/ping-pong/disabled/runner.cs
similarity index 100%
rename from tests/runtime-async/async/ping-pong/runner.cs
rename to tests/runtime/ping-pong/disabled/runner.cs
diff --git a/tests/runtime-async/async/ping-pong/test.cs b/tests/runtime/ping-pong/disabled/test.cs
similarity index 100%
rename from tests/runtime-async/async/ping-pong/test.cs
rename to tests/runtime/ping-pong/disabled/test.cs
diff --git a/tests/runtime-async/async/ping-pong/runner.c b/tests/runtime/ping-pong/runner.c
similarity index 100%
rename from tests/runtime-async/async/ping-pong/runner.c
rename to tests/runtime/ping-pong/runner.c
diff --git a/tests/runtime-async/async/ping-pong/runner.go b/tests/runtime/ping-pong/runner.go
similarity index 100%
rename from tests/runtime-async/async/ping-pong/runner.go
rename to tests/runtime/ping-pong/runner.go
diff --git a/tests/runtime-async/async/ping-pong/runner.rs b/tests/runtime/ping-pong/runner.rs
similarity index 100%
rename from tests/runtime-async/async/ping-pong/runner.rs
rename to tests/runtime/ping-pong/runner.rs
diff --git a/tests/runtime-async/async/ping-pong/test.c b/tests/runtime/ping-pong/test.c
similarity index 100%
rename from tests/runtime-async/async/ping-pong/test.c
rename to tests/runtime/ping-pong/test.c
diff --git a/tests/runtime-async/async/ping-pong/test.go b/tests/runtime/ping-pong/test.go
similarity index 100%
rename from tests/runtime-async/async/ping-pong/test.go
rename to tests/runtime/ping-pong/test.go
diff --git a/tests/runtime-async/async/ping-pong/test.rs b/tests/runtime/ping-pong/test.rs
similarity index 100%
rename from tests/runtime-async/async/ping-pong/test.rs
rename to tests/runtime/ping-pong/test.rs
diff --git a/tests/runtime-async/async/ping-pong/test.wit b/tests/runtime/ping-pong/test.wit
similarity index 93%
rename from tests/runtime-async/async/ping-pong/test.wit
rename to tests/runtime/ping-pong/test.wit
index cdfa4d43d..41468b2c8 100644
--- a/tests/runtime-async/async/ping-pong/test.wit
+++ b/tests/runtime/ping-pong/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/return-string/runner.go b/tests/runtime/return-string/runner.go
similarity index 100%
rename from tests/runtime-async/async/return-string/runner.go
rename to tests/runtime/return-string/runner.go
diff --git a/tests/runtime-async/async/return-string/test.go b/tests/runtime/return-string/test.go
similarity index 100%
rename from tests/runtime-async/async/return-string/test.go
rename to tests/runtime/return-string/test.go
diff --git a/tests/runtime-async/async/return-string/test.wit b/tests/runtime/return-string/test.wit
similarity index 90%
rename from tests/runtime-async/async/return-string/test.wit
rename to tests/runtime/return-string/test.wit
index 943d8cea7..c8b23cdaf 100644
--- a/tests/runtime-async/async/return-string/test.wit
+++ b/tests/runtime/return-string/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/rust-async-and-block-on/runner.rs b/tests/runtime/rust-async-and-block-on/runner.rs
similarity index 100%
rename from tests/runtime-async/async/rust-async-and-block-on/runner.rs
rename to tests/runtime/rust-async-and-block-on/runner.rs
diff --git a/tests/runtime-async/async/rust-async-and-block-on/test.rs b/tests/runtime/rust-async-and-block-on/test.rs
similarity index 100%
rename from tests/runtime-async/async/rust-async-and-block-on/test.rs
rename to tests/runtime/rust-async-and-block-on/test.rs
diff --git a/tests/runtime-async/async/rust-async-and-block-on/test.wit b/tests/runtime/rust-async-and-block-on/test.wit
similarity index 90%
rename from tests/runtime-async/async/rust-async-and-block-on/test.wit
rename to tests/runtime/rust-async-and-block-on/test.wit
index 3e66f4289..94ebaa738 100644
--- a/tests/runtime-async/async/rust-async-and-block-on/test.wit
+++ b/tests/runtime/rust-async-and-block-on/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface i {
diff --git a/tests/runtime-async/async/rust-cross-task-wakeup/runner.rs b/tests/runtime/rust-cross-task-wakeup/runner.rs
similarity index 100%
rename from tests/runtime-async/async/rust-cross-task-wakeup/runner.rs
rename to tests/runtime/rust-cross-task-wakeup/runner.rs
diff --git a/tests/runtime-async/async/rust-cross-task-wakeup/test.rs b/tests/runtime/rust-cross-task-wakeup/test.rs
similarity index 100%
rename from tests/runtime-async/async/rust-cross-task-wakeup/test.rs
rename to tests/runtime/rust-cross-task-wakeup/test.rs
diff --git a/tests/runtime-async/async/rust-cross-task-wakeup/test.wit b/tests/runtime/rust-cross-task-wakeup/test.wit
similarity index 91%
rename from tests/runtime-async/async/rust-cross-task-wakeup/test.wit
rename to tests/runtime/rust-cross-task-wakeup/test.wit
index ae07023b3..35e8f2dfe 100644
--- a/tests/runtime-async/async/rust-cross-task-wakeup/test.wit
+++ b/tests/runtime/rust-cross-task-wakeup/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/rust-lowered-send/runner.rs b/tests/runtime/rust-lowered-send/runner.rs
similarity index 100%
rename from tests/runtime-async/async/rust-lowered-send/runner.rs
rename to tests/runtime/rust-lowered-send/runner.rs
diff --git a/tests/runtime-async/async/rust-lowered-send/test.rs b/tests/runtime/rust-lowered-send/test.rs
similarity index 100%
rename from tests/runtime-async/async/rust-lowered-send/test.rs
rename to tests/runtime/rust-lowered-send/test.rs
diff --git a/tests/runtime-async/async/rust-lowered-send/test.wit b/tests/runtime/rust-lowered-send/test.wit
similarity index 90%
rename from tests/runtime-async/async/rust-lowered-send/test.wit
rename to tests/runtime/rust-lowered-send/test.wit
index 6ad54cc50..692778822 100644
--- a/tests/runtime-async/async/rust-lowered-send/test.wit
+++ b/tests/runtime/rust-lowered-send/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-call-import/runner.c b/tests/runtime/simple-call-import/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/runner.c
rename to tests/runtime/simple-call-import/runner.c
diff --git a/tests/runtime-async/async/simple-call-import/runner.go b/tests/runtime/simple-call-import/runner.go
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/runner.go
rename to tests/runtime/simple-call-import/runner.go
diff --git a/tests/runtime-async/async/simple-call-import/runner.rs b/tests/runtime/simple-call-import/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/runner.rs
rename to tests/runtime/simple-call-import/runner.rs
diff --git a/tests/runtime-async/async/simple-call-import/test.c b/tests/runtime/simple-call-import/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/test.c
rename to tests/runtime/simple-call-import/test.c
diff --git a/tests/runtime-async/async/simple-call-import/test.go b/tests/runtime/simple-call-import/test.go
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/test.go
rename to tests/runtime/simple-call-import/test.go
diff --git a/tests/runtime-async/async/simple-call-import/test.rs b/tests/runtime/simple-call-import/test.rs
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/test.rs
rename to tests/runtime/simple-call-import/test.rs
diff --git a/tests/runtime-async/async/simple-yield/test.wit b/tests/runtime/simple-call-import/test.wit
similarity index 88%
rename from tests/runtime-async/async/simple-yield/test.wit
rename to tests/runtime/simple-call-import/test.wit
index 378d915eb..7635d9993 100644
--- a/tests/runtime-async/async/simple-yield/test.wit
+++ b/tests/runtime/simple-call-import/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-future/runner-nostd.rs b/tests/runtime/simple-future/runner-nostd.rs
similarity index 100%
rename from tests/runtime-async/async/simple-future/runner-nostd.rs
rename to tests/runtime/simple-future/runner-nostd.rs
diff --git a/tests/runtime-async/async/simple-future/runner.c b/tests/runtime/simple-future/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-future/runner.c
rename to tests/runtime/simple-future/runner.c
diff --git a/tests/runtime-async/async/simple-future/runner.cs b/tests/runtime/simple-future/runner.cs
similarity index 100%
rename from tests/runtime-async/async/simple-future/runner.cs
rename to tests/runtime/simple-future/runner.cs
diff --git a/tests/runtime-async/async/simple-future/runner.go b/tests/runtime/simple-future/runner.go
similarity index 100%
rename from tests/runtime-async/async/simple-future/runner.go
rename to tests/runtime/simple-future/runner.go
diff --git a/tests/runtime-async/async/simple-future/runner.rs b/tests/runtime/simple-future/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-future/runner.rs
rename to tests/runtime/simple-future/runner.rs
diff --git a/tests/runtime-async/async/simple-future/test.c b/tests/runtime/simple-future/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-future/test.c
rename to tests/runtime/simple-future/test.c
diff --git a/tests/runtime-async/async/simple-future/test.cs b/tests/runtime/simple-future/test.cs
similarity index 100%
rename from tests/runtime-async/async/simple-future/test.cs
rename to tests/runtime/simple-future/test.cs
diff --git a/tests/runtime-async/async/simple-future/test.go b/tests/runtime/simple-future/test.go
similarity index 100%
rename from tests/runtime-async/async/simple-future/test.go
rename to tests/runtime/simple-future/test.go
diff --git a/tests/runtime-async/async/simple-future/test.mbt b/tests/runtime/simple-future/test.mbt
similarity index 100%
rename from tests/runtime-async/async/simple-future/test.mbt
rename to tests/runtime/simple-future/test.mbt
diff --git a/tests/runtime-async/async/simple-future/test.rs b/tests/runtime/simple-future/test.rs
similarity index 100%
rename from tests/runtime-async/async/simple-future/test.rs
rename to tests/runtime/simple-future/test.rs
diff --git a/tests/runtime-async/async/simple-future/test.wit b/tests/runtime/simple-future/test.wit
similarity index 92%
rename from tests/runtime-async/async/simple-future/test.wit
rename to tests/runtime/simple-future/test.wit
index 6a1a7d1fa..45d6517b9 100644
--- a/tests/runtime-async/async/simple-future/test.wit
+++ b/tests/runtime/simple-future/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-import-params-results/runner.c b/tests/runtime/simple-import-params-results/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/runner.c
rename to tests/runtime/simple-import-params-results/runner.c
diff --git a/tests/runtime-async/async/simple-import-params-results/runner.cs b/tests/runtime/simple-import-params-results/runner.cs
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/runner.cs
rename to tests/runtime/simple-import-params-results/runner.cs
diff --git a/tests/runtime-async/async/simple-import-params-results/runner.go b/tests/runtime/simple-import-params-results/runner.go
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/runner.go
rename to tests/runtime/simple-import-params-results/runner.go
diff --git a/tests/runtime-async/async/simple-import-params-results/runner.rs b/tests/runtime/simple-import-params-results/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/runner.rs
rename to tests/runtime/simple-import-params-results/runner.rs
diff --git a/tests/runtime-async/async/simple-import-params-results/test.c b/tests/runtime/simple-import-params-results/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/test.c
rename to tests/runtime/simple-import-params-results/test.c
diff --git a/tests/runtime-async/async/simple-import-params-results/test.cs b/tests/runtime/simple-import-params-results/test.cs
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/test.cs
rename to tests/runtime/simple-import-params-results/test.cs
diff --git a/tests/runtime-async/async/simple-import-params-results/test.go b/tests/runtime/simple-import-params-results/test.go
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/test.go
rename to tests/runtime/simple-import-params-results/test.go
diff --git a/tests/runtime-async/async/simple-import-params-results/test.mbt b/tests/runtime/simple-import-params-results/test.mbt
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/test.mbt
rename to tests/runtime/simple-import-params-results/test.mbt
diff --git a/tests/runtime-async/async/simple-import-params-results/test.rs b/tests/runtime/simple-import-params-results/test.rs
similarity index 100%
rename from tests/runtime-async/async/simple-import-params-results/test.rs
rename to tests/runtime/simple-import-params-results/test.rs
diff --git a/tests/runtime-async/async/simple-import-params-results/test.wit b/tests/runtime/simple-import-params-results/test.wit
similarity index 95%
rename from tests/runtime-async/async/simple-import-params-results/test.wit
rename to tests/runtime/simple-import-params-results/test.wit
index 567040647..828a1e14b 100644
--- a/tests/runtime-async/async/simple-import-params-results/test.wit
+++ b/tests/runtime/simple-import-params-results/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-pending-import/runner.c b/tests/runtime/simple-pending-import/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-pending-import/runner.c
rename to tests/runtime/simple-pending-import/runner.c
diff --git a/tests/runtime-async/async/simple-pending-import/runner.go b/tests/runtime/simple-pending-import/runner.go
similarity index 100%
rename from tests/runtime-async/async/simple-pending-import/runner.go
rename to tests/runtime/simple-pending-import/runner.go
diff --git a/tests/runtime-async/async/simple-pending-import/runner.rs b/tests/runtime/simple-pending-import/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-pending-import/runner.rs
rename to tests/runtime/simple-pending-import/runner.rs
diff --git a/tests/runtime-async/async/simple-pending-import/test.c b/tests/runtime/simple-pending-import/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-pending-import/test.c
rename to tests/runtime/simple-pending-import/test.c
diff --git a/tests/runtime-async/async/simple-pending-import/test.go b/tests/runtime/simple-pending-import/test.go
similarity index 100%
rename from tests/runtime-async/async/simple-pending-import/test.go
rename to tests/runtime/simple-pending-import/test.go
diff --git a/tests/runtime-async/async/simple-pending-import/test.rs b/tests/runtime/simple-pending-import/test.rs
similarity index 100%
rename from tests/runtime-async/async/simple-pending-import/test.rs
rename to tests/runtime/simple-pending-import/test.rs
diff --git a/tests/runtime-async/async/simple-pending-import/test.wit b/tests/runtime/simple-pending-import/test.wit
similarity index 88%
rename from tests/runtime-async/async/simple-pending-import/test.wit
rename to tests/runtime/simple-pending-import/test.wit
index 378d915eb..7635d9993 100644
--- a/tests/runtime-async/async/simple-pending-import/test.wit
+++ b/tests/runtime/simple-pending-import/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-stream-payload/runner.c b/tests/runtime/simple-stream-payload/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/runner.c
rename to tests/runtime/simple-stream-payload/runner.c
diff --git a/tests/runtime-async/async/simple-stream-payload/runner.cs b/tests/runtime/simple-stream-payload/runner.cs
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/runner.cs
rename to tests/runtime/simple-stream-payload/runner.cs
diff --git a/tests/runtime-async/async/simple-stream-payload/runner.go b/tests/runtime/simple-stream-payload/runner.go
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/runner.go
rename to tests/runtime/simple-stream-payload/runner.go
diff --git a/tests/runtime-async/async/simple-stream-payload/runner.rs b/tests/runtime/simple-stream-payload/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/runner.rs
rename to tests/runtime/simple-stream-payload/runner.rs
diff --git a/tests/runtime-async/async/simple-stream-payload/test.c b/tests/runtime/simple-stream-payload/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/test.c
rename to tests/runtime/simple-stream-payload/test.c
diff --git a/tests/runtime-async/async/simple-stream-payload/test.cs b/tests/runtime/simple-stream-payload/test.cs
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/test.cs
rename to tests/runtime/simple-stream-payload/test.cs
diff --git a/tests/runtime-async/async/simple-stream-payload/test.go b/tests/runtime/simple-stream-payload/test.go
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/test.go
rename to tests/runtime/simple-stream-payload/test.go
diff --git a/tests/runtime-async/async/simple-stream-payload/test.mbt b/tests/runtime/simple-stream-payload/test.mbt
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/test.mbt
rename to tests/runtime/simple-stream-payload/test.mbt
diff --git a/tests/runtime-async/async/simple-stream-payload/test.rs b/tests/runtime/simple-stream-payload/test.rs
similarity index 100%
rename from tests/runtime-async/async/simple-stream-payload/test.rs
rename to tests/runtime/simple-stream-payload/test.rs
diff --git a/tests/runtime-async/async/simple-stream-payload/test.wit b/tests/runtime/simple-stream-payload/test.wit
similarity index 90%
rename from tests/runtime-async/async/simple-stream-payload/test.wit
rename to tests/runtime/simple-stream-payload/test.wit
index b776823fd..aa882a185 100644
--- a/tests/runtime-async/async/simple-stream-payload/test.wit
+++ b/tests/runtime/simple-stream-payload/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-stream/runner-nostd.rs b/tests/runtime/simple-stream/runner-nostd.rs
similarity index 100%
rename from tests/runtime-async/async/simple-stream/runner-nostd.rs
rename to tests/runtime/simple-stream/runner-nostd.rs
diff --git a/tests/runtime-async/async/simple-stream/runner.c b/tests/runtime/simple-stream/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-stream/runner.c
rename to tests/runtime/simple-stream/runner.c
diff --git a/tests/runtime-async/async/simple-stream/runner.go b/tests/runtime/simple-stream/runner.go
similarity index 100%
rename from tests/runtime-async/async/simple-stream/runner.go
rename to tests/runtime/simple-stream/runner.go
diff --git a/tests/runtime-async/async/simple-stream/runner.rs b/tests/runtime/simple-stream/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-stream/runner.rs
rename to tests/runtime/simple-stream/runner.rs
diff --git a/tests/runtime-async/async/simple-stream/test.c b/tests/runtime/simple-stream/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-stream/test.c
rename to tests/runtime/simple-stream/test.c
diff --git a/tests/runtime-async/async/simple-stream/test.go b/tests/runtime/simple-stream/test.go
similarity index 100%
rename from tests/runtime-async/async/simple-stream/test.go
rename to tests/runtime/simple-stream/test.go
diff --git a/tests/runtime-async/async/simple-stream/test.mbt b/tests/runtime/simple-stream/test.mbt
similarity index 100%
rename from tests/runtime-async/async/simple-stream/test.mbt
rename to tests/runtime/simple-stream/test.mbt
diff --git a/tests/runtime-async/async/simple-stream/test.wit b/tests/runtime/simple-stream/test.wit
similarity index 90%
rename from tests/runtime-async/async/simple-stream/test.wit
rename to tests/runtime/simple-stream/test.wit
index bdf2bc03b..4281d2826 100644
--- a/tests/runtime-async/async/simple-stream/test.wit
+++ b/tests/runtime/simple-stream/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime-async/async/simple-yield/runner-nostd.rs b/tests/runtime/simple-yield/runner-nostd.rs
similarity index 100%
rename from tests/runtime-async/async/simple-yield/runner-nostd.rs
rename to tests/runtime/simple-yield/runner-nostd.rs
diff --git a/tests/runtime-async/async/simple-yield/runner.c b/tests/runtime/simple-yield/runner.c
similarity index 100%
rename from tests/runtime-async/async/simple-yield/runner.c
rename to tests/runtime/simple-yield/runner.c
diff --git a/tests/runtime-async/async/simple-yield/runner.rs b/tests/runtime/simple-yield/runner.rs
similarity index 100%
rename from tests/runtime-async/async/simple-yield/runner.rs
rename to tests/runtime/simple-yield/runner.rs
diff --git a/tests/runtime-async/async/simple-yield/test.c b/tests/runtime/simple-yield/test.c
similarity index 100%
rename from tests/runtime-async/async/simple-yield/test.c
rename to tests/runtime/simple-yield/test.c
diff --git a/tests/runtime-async/async/simple-yield/test.rs b/tests/runtime/simple-yield/test.rs
similarity index 100%
rename from tests/runtime-async/async/simple-yield/test.rs
rename to tests/runtime/simple-yield/test.rs
diff --git a/tests/runtime-async/async/threading-builtins/test.wit b/tests/runtime/simple-yield/test.wit
similarity index 88%
rename from tests/runtime-async/async/threading-builtins/test.wit
rename to tests/runtime/simple-yield/test.wit
index 378d915eb..7635d9993 100644
--- a/tests/runtime-async/async/threading-builtins/test.wit
+++ b/tests/runtime/simple-yield/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package a:b;
 
 interface i {
diff --git a/tests/runtime-async/async/stream-to-futures-stream/runner.rs b/tests/runtime/stream-to-futures-stream/runner.rs
similarity index 100%
rename from tests/runtime-async/async/stream-to-futures-stream/runner.rs
rename to tests/runtime/stream-to-futures-stream/runner.rs
diff --git a/tests/runtime-async/async/stream-to-futures-stream/test.rs b/tests/runtime/stream-to-futures-stream/test.rs
similarity index 100%
rename from tests/runtime-async/async/stream-to-futures-stream/test.rs
rename to tests/runtime/stream-to-futures-stream/test.rs
diff --git a/tests/runtime-async/async/stream-to-futures-stream/test.wit b/tests/runtime/stream-to-futures-stream/test.wit
similarity index 90%
rename from tests/runtime-async/async/stream-to-futures-stream/test.wit
rename to tests/runtime/stream-to-futures-stream/test.wit
index b776823fd..aa882a185 100644
--- a/tests/runtime-async/async/stream-to-futures-stream/test.wit
+++ b/tests/runtime/stream-to-futures-stream/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 package my:test;
 
 interface i {
diff --git a/tests/runtime/strings/runner.go b/tests/runtime/strings/disabled/runner.go
similarity index 100%
rename from tests/runtime/strings/runner.go
rename to tests/runtime/strings/disabled/runner.go
diff --git a/tests/runtime/strings/test.go b/tests/runtime/strings/disabled/test.go
similarity index 100%
rename from tests/runtime/strings/test.go
rename to tests/runtime/strings/disabled/test.go
diff --git a/tests/runtime-async/async/yield-loop-receives-events/leaf.rs b/tests/runtime/yield-loop-receives-events/leaf.rs
similarity index 100%
rename from tests/runtime-async/async/yield-loop-receives-events/leaf.rs
rename to tests/runtime/yield-loop-receives-events/leaf.rs
diff --git a/tests/runtime-async/async/yield-loop-receives-events/middle.rs b/tests/runtime/yield-loop-receives-events/middle.rs
similarity index 100%
rename from tests/runtime-async/async/yield-loop-receives-events/middle.rs
rename to tests/runtime/yield-loop-receives-events/middle.rs
diff --git a/tests/runtime-async/async/yield-loop-receives-events/runner.rs b/tests/runtime/yield-loop-receives-events/runner.rs
similarity index 100%
rename from tests/runtime-async/async/yield-loop-receives-events/runner.rs
rename to tests/runtime/yield-loop-receives-events/runner.rs
diff --git a/tests/runtime-async/async/yield-loop-receives-events/test.wit b/tests/runtime/yield-loop-receives-events/test.wit
similarity index 94%
rename from tests/runtime-async/async/yield-loop-receives-events/test.wit
rename to tests/runtime/yield-loop-receives-events/test.wit
index 343a5294d..6136b613b 100644
--- a/tests/runtime-async/async/yield-loop-receives-events/test.wit
+++ b/tests/runtime/yield-loop-receives-events/test.wit
@@ -1,3 +1,4 @@
+//@ async = true
 //@ dependencies = ['middle', 'leaf']
 
 package test:common;
diff --git a/tests/runtime-async/async/threading-builtins/runner.c b/tests/threading/threading-builtins/runner.c
similarity index 100%
rename from tests/runtime-async/async/threading-builtins/runner.c
rename to tests/threading/threading-builtins/runner.c
diff --git a/tests/runtime-async/async/threading-builtins/test.c b/tests/threading/threading-builtins/test.c
similarity index 100%
rename from tests/runtime-async/async/threading-builtins/test.c
rename to tests/threading/threading-builtins/test.c
diff --git a/tests/runtime-async/async/simple-call-import/test.wit b/tests/threading/threading-builtins/test.wit
similarity index 100%
rename from tests/runtime-async/async/simple-call-import/test.wit
rename to tests/threading/threading-builtins/test.wit