diff --git a/gobject/gobject.c b/gobject/gobject.c
index 6546d1ad3..f4266e3be 100644
--- a/gobject/gobject.c
+++ b/gobject/gobject.c
@@ -538,8 +538,8 @@ validate_and_install_class_property (GObjectClass *class,
                                      GParamSpec   *pspec)
 {
   g_return_val_if_fail (G_IS_PARAM_SPEC (pspec), FALSE);
-  g_return_val_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE), FALSE);
   g_return_val_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0, FALSE);	/* paranoid */
+  g_return_val_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE), FALSE);
   if (pspec->flags & G_PARAM_CONSTRUCT)
     g_return_val_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0, FALSE);
   if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))