diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index c59ea744e7..21f1e7b993 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -1,5 +1,5 @@
@@ -102,7 +102,7 @@ COMMENT
COMMENT adds a comment to an object that can be
easily retrieved with psql's
\dd command.
- To remove a comment, use ''.
+ To remove a comment, use NULL.
Comments are automatically dropped when the object is dropped.