diff --git a/bin/i3-companion b/bin/i3-companion
index c2d75ab..ba4d4c4 100755
--- a/bin/i3-companion
+++ b/bin/i3-companion
@@ -197,6 +197,9 @@ async def window_info(i3, event):
 
 
 output_update_running = None
+
+
+@on(Event.OUTPUT)
 async def output_update(i3, event):
     """React to a XRandR change."""
     global output_update_running