diff --git a/vm_core.h b/vm_core.h
index e1e3fb1e59..55ed676afe 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -21,11 +21,11 @@
 #endif
 
 #if VM_CHECK_MODE > 0
-#define VM_ASSERT(expr) do { \
-    if(!(expr)) rb_bug("%s:%d assertion violation - %s", __FILE__, __LINE__, #expr); \
-} while (0)
+#define VM_ASSERT(expr) ( \
+	LIKELY(expr) ? (void)0 : \
+	rb_bug("%s:%d assertion violation - %s", __FILE__, __LINE__, #expr))
 #else
-#define VM_ASSERT(expr)
+#define VM_ASSERT(expr) ((void)0)
 #endif
 
 #define RUBY_VM_THREAD_MODEL 2