diff --git a/doc/src/sgml/ref/alter_index.sgml b/doc/src/sgml/ref/alter_index.sgml
index 3eaf0f7291f..8a5ab030249 100644
--- a/doc/src/sgml/ref/alter_index.sgml
+++ b/doc/src/sgml/ref/alter_index.sgml
@@ -1,5 +1,5 @@
@@ -28,7 +28,7 @@ ALTER INDEX name
where action is one of:
OWNER TO new_owner
- SET INDEXSPACE indexspace_name
+ SET TABLESPACE indexspace_name