diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index c8da82217d..9d474ad5e2 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -14114,11 +14114,9 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
 	}
 
 	/*
-	 * Check whether default partition has a row that would fit the partition
-	 * being attached.
+	 * Check if the default partition contains a row that would belong in the
+	 * partition being attached.
 	 */
-	defaultPartOid =
-		get_default_oid_from_partdesc(RelationGetPartitionDesc(rel));
 	if (OidIsValid(defaultPartOid))
 	{
 		Relation	defaultrel;
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index a80d16a394..4712fab540 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -3891,3 +3891,19 @@ ALTER TABLE attmp ALTER COLUMN i RESET (n_distinct_inherited);
 ANALYZE attmp;
 DROP TABLE attmp;
 DROP USER regress_alter_table_user1;
+-- check that violating rows are correctly reported when attaching as the
+-- default partition
+create table defpart_attach_test (a int) partition by list (a);
+create table defpart_attach_test1 partition of defpart_attach_test for values in (1);
+create table defpart_attach_test_d (like defpart_attach_test);
+insert into defpart_attach_test_d values (1), (2);
+-- error because its constraint as the default partition would be violated
+-- by the row containing 1
+alter table defpart_attach_test attach partition defpart_attach_test_d default;
+ERROR:  partition constraint is violated by some row
+delete from defpart_attach_test_d where a = 1;
+alter table defpart_attach_test_d add check (a > 1);
+-- should be attached successfully and without needing to be scanned
+alter table defpart_attach_test attach partition defpart_attach_test_d default;
+INFO:  partition constraint for table "defpart_attach_test_d" is implied by existing constraints
+drop table defpart_attach_test;
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 8198d1e930..c557b050af 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -2565,3 +2565,21 @@ ANALYZE attmp;
 DROP TABLE attmp;
 
 DROP USER regress_alter_table_user1;
+
+-- check that violating rows are correctly reported when attaching as the
+-- default partition
+create table defpart_attach_test (a int) partition by list (a);
+create table defpart_attach_test1 partition of defpart_attach_test for values in (1);
+create table defpart_attach_test_d (like defpart_attach_test);
+insert into defpart_attach_test_d values (1), (2);
+
+-- error because its constraint as the default partition would be violated
+-- by the row containing 1
+alter table defpart_attach_test attach partition defpart_attach_test_d default;
+delete from defpart_attach_test_d where a = 1;
+alter table defpart_attach_test_d add check (a > 1);
+
+-- should be attached successfully and without needing to be scanned
+alter table defpart_attach_test attach partition defpart_attach_test_d default;
+
+drop table defpart_attach_test;