diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index d5dc0ce0c5..b62337bd97 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -6342,6 +6342,9 @@ CREATE FOREIGN TABLE foreign_tbl (a int, b int)
   SERVER loopback OPTIONS (table_name 'child_tbl');
 CREATE TABLE parent_tbl (a int, b int) PARTITION BY RANGE(a);
 ALTER TABLE parent_tbl ATTACH PARTITION foreign_tbl FOR VALUES FROM (0) TO (100);
+-- Detach and re-attach once, to stress the concurrent detach case.
+ALTER TABLE parent_tbl DETACH PARTITION foreign_tbl CONCURRENTLY;
+ALTER TABLE parent_tbl ATTACH PARTITION foreign_tbl FOR VALUES FROM (0) TO (100);
 CREATE VIEW rw_view AS SELECT * FROM parent_tbl
   WHERE a < b WITH CHECK OPTION;
 \d+ rw_view
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index ef45b3f91c..ee9ab37d56 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -1438,6 +1438,9 @@ CREATE FOREIGN TABLE foreign_tbl (a int, b int)
 
 CREATE TABLE parent_tbl (a int, b int) PARTITION BY RANGE(a);
 ALTER TABLE parent_tbl ATTACH PARTITION foreign_tbl FOR VALUES FROM (0) TO (100);
+-- Detach and re-attach once, to stress the concurrent detach case.
+ALTER TABLE parent_tbl DETACH PARTITION foreign_tbl CONCURRENTLY;
+ALTER TABLE parent_tbl ATTACH PARTITION foreign_tbl FOR VALUES FROM (0) TO (100);
 
 CREATE VIEW rw_view AS SELECT * FROM parent_tbl
   WHERE a < b WITH CHECK OPTION;
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index b9ea5280ef..85cb3b22a0 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -14787,8 +14787,6 @@ MarkInheritDetached(Relation child_rel, Relation parent_rel)
 	HeapTuple	inheritsTuple;
 	bool		found = false;
 
-	Assert(child_rel->rd_rel->relkind == RELKIND_RELATION ||
-		   child_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
 	Assert(parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
 
 	/*