diff --git a/common/xutil.h b/common/xutil.h
index a7ca46d34..0864feaa0 100644
--- a/common/xutil.h
+++ b/common/xutil.h
@@ -49,10 +49,6 @@ xutil_get_text_property_from_reply(xcb_get_property_reply_t *reply)
     return NULL;
 }
 
-void xutil_lock_mask_get(xcb_connection_t *, xcb_get_modifier_mapping_cookie_t,
-                         xcb_key_symbols_t *,
-                         uint16_t *, uint16_t *, uint16_t *, uint16_t *);
-
 uint16_t xutil_key_mask_fromstr(const char *);
 void xutil_key_mask_tostr(uint16_t, const char **, size_t *);