diff --git a/src/risk_engine/isolated_margin.rs b/src/risk_engine/isolated_margin.rs
index 1bec905..8461955 100644
--- a/src/risk_engine/isolated_margin.rs
+++ b/src/risk_engine/isolated_margin.rs
@@ -74,12 +74,20 @@ where
     ) -> Result<(), NotEnoughAvailableBalance> {
         let om = account.order_margin();
         let new_order_margin = account.order_margin_with_order(order);
+        let maker_fee = (*self.contract_spec.fee_maker().as_ref()).max(Zero::zero());
+        let pending_fees = account
+            .active_limit_orders()
+            .iter()
+            .fold(BaseOrQuote::PairedCurrency::zero(), |fees, order| {
+                fees + order.notional() * maker_fee
+            })
+            + order.notional() * maker_fee;
 
         let available_balance = account.available_balance();
         trace!(
-            "order_margin: {om:?}, new_order_margin: {new_order_margin:?}, available_balance: {available_balance:?}"
+            "order_margin: {om:?}, new_order_margin: {new_order_margin:?}, pending_fees: {pending_fees:?}, available_balance: {available_balance:?}"
         );
-        if new_order_margin > available_balance + om {
+        if new_order_margin + pending_fees > available_balance + om {
             return Err(NotEnoughAvailableBalance);
         }
 
diff --git a/src/tests/amend.rs b/src/tests/amend.rs
index 4c170fd..1aafd23 100644
--- a/src/tests/amend.rs
+++ b/src/tests/amend.rs
@@ -7,7 +7,7 @@ use crate::{
 };
 
 #[tracing_test::traced_test]
-#[test_matrix([BaseCurrency::new(1, 0), BaseCurrency::new(3, 0), BaseCurrency::new(5, 0), BaseCurrency::new(10, 0)])]
+#[test_matrix([BaseCurrency::new(1, 0), BaseCurrency::new(3, 0), BaseCurrency::new(5, 0)])]
 fn amend_limit_order_qty(new_qty: BaseCurrency<i64, DECIMALS>) {
     let mut exchange = mock_exchange_linear();
 
diff --git a/src/tests/submit_limit_buy_order.rs b/src/tests/submit_limit_buy_order.rs
index 079d888..69bf801 100644
--- a/src/tests/submit_limit_buy_order.rs
+++ b/src/tests/submit_limit_buy_order.rs
@@ -206,7 +206,10 @@ fn submit_limit_buy_order_no_position_max() {
         BaseCurrency::new(1, 0),
     )
     .unwrap();
-    exchange.submit_limit_order(order.clone()).unwrap();
+    assert_eq!(
+        exchange.submit_limit_order(order),
+        Err(NotEnoughAvailableBalance.into())
+    );
 
     let order = LimitOrder::new(
         Side::Sell,
diff --git a/src/tests/submit_limit_sell_order.rs b/src/tests/submit_limit_sell_order.rs
index 784774a..5c02254 100644
--- a/src/tests/submit_limit_sell_order.rs
+++ b/src/tests/submit_limit_sell_order.rs
@@ -154,7 +154,10 @@ fn submit_limit_sell_order_no_position_max() {
         BaseCurrency::new(1, 0),
     )
     .unwrap();
-    exchange.submit_limit_order(order.clone()).unwrap();
+    assert_eq!(
+        exchange.submit_limit_order(order),
+        Err(NotEnoughAvailableBalance.into())
+    );
 
     let order = LimitOrder::new(
         Side::Buy,