diff --git a/src/jrd/ExtEngineManager.cpp b/src/jrd/ExtEngineManager.cpp
index 782eadc7e2..dec3ca410d 100644
--- a/src/jrd/ExtEngineManager.cpp
+++ b/src/jrd/ExtEngineManager.cpp
@@ -1140,7 +1140,7 @@ namespace
 		}
 
 	public:
-		virtual int release() override
+		int release() override
 		{
 			// Never delete static instance of SystemEngine
 			return 1;