--- ext/gtk2/rbgdkscreen.c.orig	2023-06-13 15:11:58 UTC
+++ ext/gtk2/rbgdkscreen.c
@@ -255,7 +255,7 @@ rg_window_stack(VALUE self)
 static void
 child_setup(gpointer func)
 {
-    if (! NIL_P(func)){
+    if (! NIL_P((VALUE) func)){
         rb_funcall((VALUE)func, id_call, 0);
     }
 }
--- ext/gtk2/rbgtkdrag.c.orig	2023-06-13 15:21:51 UTC
+++ ext/gtk2/rbgtkdrag.c
@@ -358,7 +358,7 @@ static VALUE
 rg_m_source_get_target_list(G_GNUC_UNUSED VALUE self, VALUE widget)
 {
     GtkTargetList* ret = gtk_drag_source_get_target_list(RVAL2WIDGET(widget));
-    return NIL_P(ret) ? Qnil : BOXED2RVAL(ret, GTK_TYPE_TARGET_LIST);
+    return NIL_P((VALUE) ret) ? Qnil : BOXED2RVAL(ret, GTK_TYPE_TARGET_LIST);
 }
 
 static VALUE