diff --git a/configure.ac b/configure.ac
index 847c4f0f8..eb731d341 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3358,8 +3358,8 @@ $ac_cv_sizeof_int)
   gintptr_modifier='""'
   gintptr_format='"i"'
   guintptr_format='"u"'
-  glib_gpi_cast=''
-  glib_gpui_cast=''
+  glib_gpi_cast='gint'
+  glib_gpui_cast='guint'
   ;;
 $ac_cv_sizeof_long)
   glib_intptr_type_define=long