diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index cd9c3eddd1d..c31d6fc1fb8 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2499,6 +2499,11 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
 								 conForm->connoinherit ? " NO INHERIT" : "");
 				break;
 			}
+
+		case CONSTRAINT_NOTNULL:
+			appendStringInfoString(&buf, "NOT NULL");
+			break;
+
 		case CONSTRAINT_TRIGGER:
 
 			/*