diff --git a/include/spdlog/sinks/null_sink.h b/include/spdlog/sinks/null_sink.h
index 68bd9c94..1d427aa2 100644
--- a/include/spdlog/sinks/null_sink.h
+++ b/include/spdlog/sinks/null_sink.h
@@ -27,7 +27,7 @@ protected:
 
 };
 typedef null_sink<details::null_mutex> null_sink_st;
-typedef null_sink<std::mutex> null_sink_mt;
+typedef null_sink<details::null_mutex> null_sink_mt;
 
 }
 }