diff --git a/unix/x0vncserver/XDesktop.cxx b/unix/x0vncserver/XDesktop.cxx
index 0273a6d..110b79e 100644
--- a/unix/x0vncserver/XDesktop.cxx
+++ b/unix/x0vncserver/XDesktop.cxx
@@ -346,14 +346,18 @@
     }
   }
 
-  if (!keycode)
+  if (!keycode) {
+    vlog.error("Could not map key event to X11 key code");
     return;
+  }
 
   if (down)
     pressedKeys[keysym] = keycode;
   else
     pressedKeys.erase(keysym);
 
+  vlog.debug("%d %s", keycode, down ? "down" : "up");
+
   XTestFakeKeyEvent(dpy, keycode, down, CurrentTime);
 #endif
 }