diff --git a/reactos/lib/rtl/srw.c b/reactos/lib/rtl/srw.c
index 4fe2e57b529..11e409e8b70 100644
--- a/reactos/lib/rtl/srw.c
+++ b/reactos/lib/rtl/srw.c
@@ -50,7 +50,7 @@
 #define ASSERT_SRW_WAITBLOCK(ptr) \
     ASSERT(((ULONG_PTR)ptr & ((1 << RTL_SRWLOCK_BITS) - 1)) == 0)
 #else
-#define ASSERT_SRW_WAITBLOCK(ptr)
+#define ASSERT_SRW_WAITBLOCK(ptr) ((void)0)
 #endif
 
 typedef struct _RTLP_SRWLOCK_SHARED_WAKE