diff --git a/src/lib/platform/OSXScreen.cpp b/src/lib/platform/OSXScreen.cpp
index 182d6e53..2a4c5c4a 100644
--- a/src/lib/platform/OSXScreen.cpp
+++ b/src/lib/platform/OSXScreen.cpp
@@ -1941,7 +1941,7 @@ OSXScreen::handleCGInputEvent(CGEventTapProxy proxy,
 		case NX_NULLEVENT:
 			break;
 		case NX_SYSDEFINED:
-			// Unknown, forward it
+			LOG((CLOG_DEBUG2 "unknown system defined event"));
 			return event;
 			break;
 		case NX_NUMPROCS: