diff --git a/lib/XMonad/Internal/Command/DMenu.hs b/lib/XMonad/Internal/Command/DMenu.hs
index 2d6de6a..2fb2477 100644
--- a/lib/XMonad/Internal/Command/DMenu.hs
+++ b/lib/XMonad/Internal/Command/DMenu.hs
@@ -203,6 +203,7 @@ showKeys :: [((KeyMask, KeySym), NamedAction)] -> X ()
 showKeys kbs = do
   h <- spawnPipe cmd
   io $ hPutStr h $ unlines $ showKm kbs
+  io $ hClose h
   where
     cmd = fmtCmd myDmenuCmd $ ["-dmenu", "-p", "commands"]
       ++ themeArgs "#7f66ff" ++ myDmenuMatchingArgs