diff --git a/reactos/hal/hal/hal.c b/reactos/hal/hal/hal.c
index 6547e251ab3..21f0be33430 100644
--- a/reactos/hal/hal/hal.c
+++ b/reactos/hal/hal/hal.c
@@ -18,6 +18,10 @@
 #define NDEBUG
 #include <debug.h>
 
+#undef ExAcquireFastMutex
+#undef ExReleaseFastMutex
+#undef ExTryToAcquireFastMutex
+
 /* DATA **********************************************************************/
 
 ULONG KdComPortInUse = 0;