diff --git a/src/ui/ui.c b/src/ui/ui.c
index 1acb70c44..2c2166bfc 100644
--- a/src/ui/ui.c
+++ b/src/ui/ui.c
@@ -81,7 +81,7 @@ is_interesting_input_event (XEvent *event)
   XIEvent *input_event;
 
   if (event->type != GenericEvent ||
-      event->xcookie.extension == display->xinput_opcode)
+      event->xcookie.extension != display->xinput_opcode)
     return FALSE;
 
   input_event = (XIEvent *) event->xcookie.data;