diff --git a/pyproject.toml b/pyproject.toml
index a64f94d..09597e4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -102,7 +102,7 @@ ci = [
     "mkdocs-llmstxt>=0.2",
     "mkdocs-material>=9.5",
     "mkdocs-minify-plugin>=0.8",
-    "mkdocs-section-index>=0.3",
+    "mkdocs-section-index>=0.3.12",
     "mkdocstrings[python]>=0.29",
     "pydantic>=2.13.4",
     # YORE: EOL 3.10: Remove line.
diff --git a/test_zig_project/uv.lock b/test_zig_project/uv.lock
index 2c3fc9a..6c35806 100644
--- a/test_zig_project/uv.lock
+++ b/test_zig_project/uv.lock
@@ -436,7 +436,7 @@ docs = [
     { name = "mkdocs-llmstxt", specifier = ">=0.2" },
     { name = "mkdocs-material", specifier = ">=9.5" },
     { name = "mkdocs-minify-plugin", specifier = ">=0.8" },
-    { name = "mkdocs-section-index", specifier = ">=0.3" },
+    { name = "mkdocs-section-index", specifier = ">=0.3.12" },
     { name = "mkdocstrings", extras = ["python"], specifier = ">=0.29" },
     { name = "pydantic", specifier = ">=2.13.4" },
     { name = "tomli", marker = "python_full_version < '3.11'", specifier = ">=2.0" },