diff --git a/src/insexpand.c b/src/insexpand.c
index 54f8cb3..454e2e3 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -576,8 +576,8 @@
     char_u	*str,
     int		len,
     char_u	*fname,
-    char_u	**cptext,	// extra text for popup menu or NULL
-    typval_T	*user_data,	// "user_data" entry or NULL
+    char_u	**cptext,	    // extra text for popup menu or NULL
+    typval_T	*user_data UNUSED,  // "user_data" entry or NULL
     int		cdir,
     int		flags_arg,
     int		adup)		// accept duplicate match