diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index c145385f84..2d0043d1db 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -14247,9 +14247,6 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
 						trigger_name, RelationGetRelationName(attachrel)),
 				 errdetail("ROW triggers with transition tables are not supported on partitions")));
 
-	/* OK to create inheritance.  Rest of the checks performed there */
-	CreateInheritance(attachrel, rel);
-
 	/*
 	 * Check that the new partition's bound is valid and does not overlap any
 	 * of existing partitions of the parent - note that it does not return on
@@ -14258,6 +14255,9 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
 	check_new_partition_bound(RelationGetRelationName(attachrel), rel,
 							  cmd->bound);
 
+	/* OK to create inheritance.  Rest of the checks performed there */
+	CreateInheritance(attachrel, rel);
+
 	/* Update the pg_class entry. */
 	StorePartitionBound(attachrel, rel, cmd->bound);
 
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index dccc9b27c5..be0b54cc52 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -3960,3 +3960,18 @@ ERROR:  cannot attach a temporary relation as partition of permanent relation "p
 alter table temp_part_parent attach partition temp_part_child default; -- ok
 drop table perm_part_parent cascade;
 drop table temp_part_parent cascade;
+-- test case where the partitioning operator is a SQL function whose
+-- evaluation results in the table's relcache being rebuilt partway through
+-- the execution of an ATTACH PARTITION command
+create function at_test_sql_partop (int4, int4) returns int language sql
+as $$ select case when $1 = $2 then 0 when $1 > $2 then 1 else -1 end; $$;
+create operator class at_test_sql_partop for type int4 using btree as
+    operator 1 < (int4, int4), operator 2 <= (int4, int4),
+    operator 3 = (int4, int4), operator 4 >= (int4, int4),
+    operator 5 > (int4, int4), function 1 at_test_sql_partop(int4, int4);
+create table at_test_sql_partop (a int) partition by range (a at_test_sql_partop);
+create table at_test_sql_partop_1 (a int);
+alter table at_test_sql_partop attach partition at_test_sql_partop_1 for values from (0) to (10);
+drop table at_test_sql_partop;
+drop operator class at_test_sql_partop using btree;
+drop function at_test_sql_partop;
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index b90497804b..179bbfb9a1 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -2618,3 +2618,19 @@ alter table perm_part_parent attach partition temp_part_child default; -- error
 alter table temp_part_parent attach partition temp_part_child default; -- ok
 drop table perm_part_parent cascade;
 drop table temp_part_parent cascade;
+
+-- test case where the partitioning operator is a SQL function whose
+-- evaluation results in the table's relcache being rebuilt partway through
+-- the execution of an ATTACH PARTITION command
+create function at_test_sql_partop (int4, int4) returns int language sql
+as $$ select case when $1 = $2 then 0 when $1 > $2 then 1 else -1 end; $$;
+create operator class at_test_sql_partop for type int4 using btree as
+    operator 1 < (int4, int4), operator 2 <= (int4, int4),
+    operator 3 = (int4, int4), operator 4 >= (int4, int4),
+    operator 5 > (int4, int4), function 1 at_test_sql_partop(int4, int4);
+create table at_test_sql_partop (a int) partition by range (a at_test_sql_partop);
+create table at_test_sql_partop_1 (a int);
+alter table at_test_sql_partop attach partition at_test_sql_partop_1 for values from (0) to (10);
+drop table at_test_sql_partop;
+drop operator class at_test_sql_partop using btree;
+drop function at_test_sql_partop;