diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 3bfaa663699..09066db0956 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -572,11 +572,7 @@ mark_index_clustered(Relation rel, Oid indexOid, bool is_internal)
 	Relation	pg_index;
 	ListCell   *index;
 
-	/* Disallow applying to a partitioned table */
-	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot mark index clustered in partitioned table")));
+	Assert(rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE);
 
 	/*
 	 * If the index is already marked clustered, no need to do anything.
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a2e3b72f156..991f3b85df7 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -5164,7 +5164,7 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 		case AT_ClusterOn:		/* CLUSTER ON */
 		case AT_DropCluster:	/* SET WITHOUT CLUSTER */
 			ATSimplePermissions(cmd->subtype, rel,
-								ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW);
+								ATT_TABLE | ATT_MATVIEW);
 			/* These commands never recurse */
 			/* No command-specific prep needed */
 			pass = AT_PASS_MISC;
diff --git a/src/test/regress/expected/cluster.out b/src/test/regress/expected/cluster.out
index 24b0b1a8fce..269f163efa6 100644
--- a/src/test/regress/expected/cluster.out
+++ b/src/test/regress/expected/cluster.out
@@ -492,9 +492,11 @@ Number of partitions: 3 (Use \d+ to list them.)
 CLUSTER clstrpart;
 ERROR:  there is no previously clustered index for table "clstrpart"
 ALTER TABLE clstrpart SET WITHOUT CLUSTER;
-ERROR:  cannot mark index clustered in partitioned table
+ERROR:  ALTER action SET WITHOUT CLUSTER cannot be performed on relation "clstrpart"
+DETAIL:  This operation is not supported for partitioned tables.
 ALTER TABLE clstrpart CLUSTER ON clstrpart_idx;
-ERROR:  cannot mark index clustered in partitioned table
+ERROR:  ALTER action CLUSTER ON cannot be performed on relation "clstrpart"
+DETAIL:  This operation is not supported for partitioned tables.
 -- and they cannot get an index-ordered REPACK without an explicit index name
 REPACK clstrpart USING INDEX;
 ERROR:  cannot execute REPACK on partitioned table "clstrpart" USING INDEX with no index name