diff --git a/src/QBar/Core.hs b/src/QBar/Core.hs
index 8a235cfa7e9da14ee401c0fbf00e27f381ae353d..c08557e44d7fc846c09471c54e02cff3387facc2 100644
--- a/src/QBar/Core.hs
+++ b/src/QBar/Core.hs
@@ -89,7 +89,7 @@ newtype BarUpdateChannel = BarUpdateChannel (IO ())
 type BarUpdateEvent = Event.Event
 
 
-class (Monad m) => MonadBarIO m where
+class (MonadIO m) => MonadBarIO m where
   liftBarIO :: BarIO a -> m a
 instance MonadBarIO BarIO where
   liftBarIO = id