diff --git a/src/cpp/ripple/InstanceCounter.h b/src/cpp/ripple/InstanceCounter.h
index 5a8fe1c612..b4c37c5ebb 100644
--- a/src/cpp/ripple/InstanceCounter.h
+++ b/src/cpp/ripple/InstanceCounter.h
@@ -82,7 +82,7 @@ public:
 	}
 	int getCount()
 	{
-		boost::mutex::scoped_lock(mLock);
+		boost::mutex::scoped_lock sl(mLock);
 		return mInstances;
 	}
 	const std::string& getName()