diff --git a/pyrseas/dbobject/constraint.py b/pyrseas/dbobject/constraint.py
index f1413d7..12f932c 100644
--- a/pyrseas/dbobject/constraint.py
+++ b/pyrseas/dbobject/constraint.py
@@ -148,6 +148,8 @@ def query(dbversion=None):
               AND contype = 'c'
               AND contypid NOT IN (SELECT objid FROM pg_depend
                   WHERE deptype = 'e' AND classid = 'pg_type'::regclass)
+              AND conrelid NOT IN (SELECT objid FROM pg_depend
+                  WHERE deptype = 'e' AND classid = 'pg_class'::regclass)
             ORDER BY schema, "table", name"""
 
     @staticmethod