diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index 5354a04639..e3e4ab636b 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -744,6 +744,9 @@ TupleDescInitBuiltinEntry(TupleDesc desc,
 			att->attstorage = 'p';
 			att->attcollation = InvalidOid;
 			break;
+
+		default:
+			elog(ERROR, "unsupported type %u", oidtypeid);
 	}
 }