diff -up qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h.me qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h
--- qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h.me	2021-05-31 21:26:39.137033058 +0200
+++ qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h	2021-05-31 21:26:45.312412620 +0200
@@ -29,9 +29,6 @@
 #include <wtf/RefPtr.h>
 #include <algorithm>
 
-extern "C" void g_object_unref(gpointer);
-extern "C" gpointer g_object_ref_sink(gpointer);
-
 namespace WTF {
 
 enum GRefPtrAdoptType { GRefPtrAdopt };