diff --git a/gobject/gsignal.c b/gobject/gsignal.c
index c83c433d2..f08729291 100644
--- a/gobject/gsignal.c
+++ b/gobject/gsignal.c
@@ -1233,8 +1233,8 @@ g_signal_lookup (const gchar *name,
     {
       /* give elaborate warnings */
       if (!g_type_name (itype))
-	g_critical (G_STRLOC ": unable to look up signal \"%s\" for invalid type id '%"G_GSIZE_FORMAT"'",
-		    name, itype);
+	g_critical (G_STRLOC ": unable to look up signal \"%s\" for invalid type id '%"G_GUINTPTR_FORMAT"'",
+		    name, (guintptr) itype);
       else if (!g_signal_is_valid_name (name))
         g_critical (G_STRLOC ": unable to look up invalid signal name \"%s\" on type '%s'",
                     name, g_type_name (itype));
@@ -1282,8 +1282,8 @@ g_signal_list_ids (GType  itype,
     {
       /* give elaborate warnings */
       if (!g_type_name (itype))
-	g_critical (G_STRLOC ": unable to list signals for invalid type id '%"G_GSIZE_FORMAT"'",
-		    itype);
+	g_critical (G_STRLOC ": unable to list signals for invalid type id '%"G_GUINTPTR_FORMAT"'",
+		    (guintptr) itype);
       else if (!G_TYPE_IS_INSTANTIATABLE (itype) && !G_TYPE_IS_INTERFACE (itype))
 	g_critical (G_STRLOC ": unable to list signals of non instantiatable type '%s'",
 		    g_type_name (itype));
@@ -2034,8 +2034,8 @@ g_signal_override_class_handler (const gchar *signal_name,
     g_signal_override_class_closure (signal_id, instance_type,
                                      g_cclosure_new (class_handler, NULL, NULL));
   else
-    g_critical ("%s: signal name '%s' is invalid for type id '%"G_GSIZE_FORMAT"'",
-                G_STRLOC, signal_name, instance_type);
+    g_critical ("%s: signal name '%s' is invalid for type id '%"G_GUINTPTR_FORMAT"'",
+                G_STRLOC, signal_name, (guintptr) instance_type);
 
 }
 
diff --git a/gobject/gtype.c b/gobject/gtype.c
index 17a950780..8222fc493 100644
--- a/gobject/gtype.c
+++ b/gobject/gtype.c
@@ -2721,9 +2721,9 @@ g_type_register_fundamental (GType                       type_id,
   if ((type_id & TYPE_ID_MASK) ||
       type_id > G_TYPE_FUNDAMENTAL_MAX)
     {
-      g_critical ("attempt to register fundamental type '%s' with invalid type id (%" G_GSIZE_FORMAT ")",
+      g_critical ("attempt to register fundamental type '%s' with invalid type id (%" G_GUINTPTR_FORMAT ")",
 		  type_name,
-		  type_id);
+		  (guintptr) type_id);
       return 0;
     }
   if ((finfo->type_flags & G_TYPE_FLAG_INSTANTIATABLE) &&
@@ -4390,7 +4390,7 @@ g_type_value_table_peek (GType type)
     return vtable;
   
   if (!node)
-    g_critical (G_STRLOC ": type id '%" G_GSIZE_FORMAT "' is invalid", type);
+    g_critical (G_STRLOC ": type id '%" G_GUINTPTR_FORMAT "' is invalid", (guintptr) type);
   if (!has_refed_data)
     g_critical ("can't peek value table for type '%s' which is not currently referenced",
 	        type_descriptive_name_I (type));