1 files changed, 2 insertions, 2 deletions
diff --git a/common/mutex.h b/common/mutex.h
index ba5c45c30e..3addaa6b18 100644
--- a/common/mutex.h
+++ b/common/mutex.h
@@ -49,8 +49,8 @@ class StackLock {
 	void lock();
 	void unlock();
 public:
-	StackLock(MutexRef mutex, const char *mutexName = NULL);
-	StackLock(const Mutex &mutex, const char *mutexName = NULL);
+	explicit StackLock(MutexRef mutex, const char *mutexName = NULL);
+	explicit StackLock(const Mutex &mutex, const char *mutexName = NULL);
 	~StackLock();
 };