diff --git a/moo/mooedit/gtksourceiter.c b/moo/mooedit/gtksourceiter.c
index f43c5917..9c845111 100644
--- a/moo/mooedit/gtksourceiter.c
+++ b/moo/mooedit/gtksourceiter.c
@@ -204,7 +204,7 @@ finally_2:
 static void
 forward_chars_with_skipping (GtkTextIter *iter,
 			     gint         count,
-			     gboolean     skip_invisible,
+			     G_GNUC_UNUSED gboolean skip_invisible,
 			     gboolean     skip_nontext,
 			     gboolean     skip_decomp)
 {