diff --git a/doc/src/sgml/ref/alter_table_subpartition.sgmlin b/doc/src/sgml/ref/alter_table_subpartition.sgmlin
index 780d2be2a..8c290a27a 100644
--- a/doc/src/sgml/ref/alter_table_subpartition.sgmlin
+++ b/doc/src/sgml/ref/alter_table_subpartition.sgmlin
@@ -26,7 +26,7 @@ PARTITION partition_name VALUES LESS THAN ( partition_value | MAXVALUE ) [ TABLE
 where partition_list_item can be:
 PARTITION partition_name VALUES ( partition_value [, ...] | DEFAULT ) [ TABLESPACE tablespacename ]
 where subpartition_definition_list can be:
-SUBPARTITION subpartition_name [ VALUES LESS THAN ( partition_value | MAXVALUE ) | VALUES ( partition_value [, ...] | DEFAULT )]  [ TABLESPACE tablespace ]
+SUBPARTITION subpartition_name { VALUES LESS THAN ( partition_value | MAXVALUE ) | VALUES ( partition_value [, ...] | DEFAULT ) }  [ TABLESPACE tablespace ]
 where drop_clause can be:
 DROP PARTITION  { partition_name | FOR (  partition_value )  } [ UPDATE GLOBAL INDEX ]
 DROP SUBPARTITION  { subpartition_name | FOR (  partition_value, subpartition_value )  } [ UPDATE GLOBAL INDEX ]
diff --git a/src/test/regress/expected/hw_subpartition_alter_table.out b/src/test/regress/expected/hw_subpartition_alter_table.out
index c6d7d7c30..ba9a928f1 100644
--- a/src/test/regress/expected/hw_subpartition_alter_table.out
+++ b/src/test/regress/expected/hw_subpartition_alter_table.out
@@ -238,7 +238,7 @@ PARTITION partition_name VALUES LESS THAN ( partition_value | MAXVALUE ) [ TABLE
 where partition_list_item can be:
 PARTITION partition_name VALUES ( partition_value [, ...] | DEFAULT ) [ TABLESPACE tablespacename ]
 where subpartition_definition_list can be:
-SUBPARTITION subpartition_name [ VALUES LESS THAN ( partition_value | MAXVALUE ) | VALUES ( partition_value [, ...] | DEFAULT )]  [ TABLESPACE tablespace ]
+SUBPARTITION subpartition_name { VALUES LESS THAN ( partition_value | MAXVALUE ) | VALUES ( partition_value [, ...] | DEFAULT ) }  [ TABLESPACE tablespace ]
 where drop_clause can be:
 DROP PARTITION  { partition_name | FOR (  partition_value )  } [ UPDATE GLOBAL INDEX ]
 DROP SUBPARTITION  { subpartition_name | FOR (  partition_value, subpartition_value )  } [ UPDATE GLOBAL INDEX ]