diff --git a/base/mutex.h b/base/mutex.h
index 14a8c576ec..fb0affa384 100644
--- a/base/mutex.h
+++ b/base/mutex.h
@@ -96,7 +96,7 @@ public:
 
 	bool trylock() {
 #ifdef _WIN32
-		return TryEnterCriticalSection(&mut_) == TRUE;
+		return TryEnterCriticalSection(&mut_) != FALSE;
 #else
 		return pthread_mutex_trylock(&mut_) != EBUSY;
 #endif