diff --git a/src/GF/System/NoSpeechInput.hs b/src/GF/System/NoSpeechInput.hs
index b9bf0f067..ca78bc3ee 100644
--- a/src/GF/System/NoSpeechInput.hs
+++ b/src/GF/System/NoSpeechInput.hs
@@ -20,4 +20,4 @@ import GF.Conversion.Types (CGrammar)
 
 recognizeSpeech :: Ident -- ^ Grammar name
 	        -> Options -> CGrammar -> IO String
-recognizeSpeech = fail "No speech input available"
+recognizeSpeech _ _ _ = fail "No speech input available"