diff --git a/src/GF/System/NoSpeechInput.hs b/src/GF/System/NoSpeechInput.hs
index 2f967f66f..b9bf0f067 100644
--- a/src/GF/System/NoSpeechInput.hs
+++ b/src/GF/System/NoSpeechInput.hs
@@ -14,4 +14,10 @@
 
 module GF.System.NoSpeechInput (recognizeSpeech) where
 
+import GF.Infra.Ident (Ident)
+import GF.Infra.Option (Options)
+import GF.Conversion.Types (CGrammar)
+
+recognizeSpeech :: Ident -- ^ Grammar name
+	        -> Options -> CGrammar -> IO String
 recognizeSpeech = fail "No speech input available"