diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 493a6bf790..6ef612dc4a 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.158 2005/07/26 16:38:26 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.159 2005/07/26 22:37:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -377,6 +377,10 @@ CreateRole(CreateRoleStmt *stmt)
 
 /*
  * ALTER ROLE
+ *
+ * Note: the rolemembers option accepted here is intended to support the
+ * backwards-compatible ALTER GROUP syntax.  Although it will work to say
+ * "ALTER ROLE role ROLE rolenames", we don't document it.
  */
 void
 AlterRole(AlterRoleStmt *stmt)
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 4d21d4eb9f..3ce9ec411b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.503 2005/07/26 16:38:27 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.504 2005/07/26 22:37:50 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -728,6 +728,7 @@ AlterRoleStmt:
 				 {
 					AlterRoleStmt *n = makeNode(AlterRoleStmt);
 					n->role = $3;
+					n->action = +1;	/* add, if there are members */
 					n->options = $5;
 					$$ = (Node *)n;
 				 }
@@ -764,6 +765,7 @@ AlterUserStmt:
 				 {
 					AlterRoleStmt *n = makeNode(AlterRoleStmt);
 					n->role = $3;
+					n->action = +1;	/* add, if there are members */
 					n->options = $5;
 					$$ = (Node *)n;
 				 }