diff --git a/src/vstdlib/keyvaluessystem.h b/src/vstdlib/keyvaluessystem.h
index df888747..2541a209 100644
--- a/src/vstdlib/keyvaluessystem.h
+++ b/src/vstdlib/keyvaluessystem.h
@@ -104,7 +104,7 @@ private:
 	CUtlRBTree<MemoryLeakTracker_t, int> m_KeyValuesTrackingList;
 	CUtlMap<HKeySymbol, bool> m_KvConditionalSymbolTable;
 
-	CThreadFastMutex m_Mutex;
+	CThreadMutex m_Mutex;
 };
 
 ///////////////////////////////////////////////////////////////////////////////