diff --git a/src/gui_gtk_x11.c b/src/gui_gtk_x11.c
index 37858dc..cd30609 100644
--- a/src/gui_gtk_x11.c
+++ b/src/gui_gtk_x11.c
@@ -598,6 +598,14 @@
     gui_argv[gui_argc] = NULL;
 }
 
+#if defined(EXITFREE) || defined(PROTO)
+    void
+gui_mch_free_all()
+{
+    vim_free(gui_argv);
+}
+#endif
+
 /*
  * This should be maybe completely removed.
  * Doesn't seem possible, since check_copy_area() relies on