diff --git a/dlls/hal/hal.c b/dlls/hal/hal.c
index 5b384264c13..3353d04ee4a 100644
--- a/dlls/hal/hal.c
+++ b/dlls/hal/hal.c
@@ -73,6 +73,17 @@ VOID WINAPI ExReleaseFastMutex(PFAST_MUTEX FastMutex)
     FIXME("%p: stub\n", FastMutex);
 }
 
+#ifdef DEFINE_FASTCALL1_ENTRYPOINT
+DEFINE_FASTCALL1_ENTRYPOINT( ExTryToAcquireFastMutex )
+BOOLEAN WINAPI __regs_ExTryToAcquireFastMutex(PFAST_MUTEX FastMutex)
+#else
+BOOLEAN WINAPI ExTryToAcquireFastMutex(PFAST_MUTEX FastMutex)
+#endif
+{
+    FIXME("(%p) stub\n", FastMutex);
+    return TRUE;
+}
+
 #ifdef DEFINE_FASTCALL1_ENTRYPOINT
 DEFINE_FASTCALL1_ENTRYPOINT( KfAcquireSpinLock )
 KIRQL WINAPI __regs_KfAcquireSpinLock(PKSPIN_LOCK SpinLock)
diff --git a/dlls/hal/hal.spec b/dlls/hal/hal.spec
index 30de7225a48..2a8c15591a4 100644
--- a/dlls/hal/hal.spec
+++ b/dlls/hal/hal.spec
@@ -1,6 +1,6 @@
 @ stdcall -norelay ExAcquireFastMutex(ptr)
 @ stdcall -norelay ExReleaseFastMutex(ptr)
-@ stub ExTryToAcquireFastMutex
+@ stdcall -norelay ExTryToAcquireFastMutex(ptr)
 @ stub HalClearSoftwareInterrupt
 @ stub HalRequestSoftwareInterrupt
 @ stub HalSystemVectorDispatchEntry