diff --git a/contrib/userlock/user_locks.c b/contrib/userlock/user_locks.c
index c3a6e8676bba6098e03330d7b7f9468b49228c70..27415dabb903c3fd91b6b3baed235a55ec8eea17 100644
--- a/contrib/userlock/user_locks.c
+++ b/contrib/userlock/user_locks.c
@@ -16,66 +16,63 @@
 
 #include "postgres.h"
 #include "miscadmin.h"
-#include "storage/lock.h"
+#include "storage/lmgr.h"
 #include "storage/proc.h"
-#include "storage/multilev.h"
 #include "utils/elog.h"
 
 #include "user_locks.h"
 
 int
-user_lock(unsigned int id1, unsigned int id2, LOCKMODE lockmode)
+user_lock(uint32 id1, uint32 id2, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
 	memset(&tag, 0, sizeof(LOCKTAG));
 	tag.dbId = MyDatabaseId;
 	tag.relId = 0;
-	tag.tupleId.ip_blkid.bi_hi = id2 >> 16;
-	tag.tupleId.ip_blkid.bi_lo = id2 & 0xffff;
-	tag.tupleId.ip_posid = (unsigned short) (id1 & 0xffff);
+	tag.objId.blkno = (BlockNumber) id2;
+	tag.offnum = (OffsetNumber) (id1 & 0xffff);
 
 	return LockAcquire(USER_LOCKMETHOD, &tag, lockmode);
 }
 
 int
-user_unlock(unsigned int id1, unsigned int id2, LOCKMODE lockmode)
+user_unlock(uint32 id1, uint32 id2, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
 	memset(&tag, 0, sizeof(LOCKTAG));
 	tag.dbId = MyDatabaseId;
 	tag.relId = 0;
-	tag.tupleId.ip_blkid.bi_hi = id2 >> 16;
-	tag.tupleId.ip_blkid.bi_lo = id2 & 0xffff;
-	tag.tupleId.ip_posid = (unsigned short) (id1 & 0xffff);
+	tag.objId.blkno = (BlockNumber) id2;
+	tag.offnum = (OffsetNumber) (id1 & 0xffff);
 
 	return LockRelease(USER_LOCKMETHOD, &tag, lockmode);
 }
 
 int
-user_write_lock(unsigned int id1, unsigned int id2)
+user_write_lock(uint32 id1, uint32 id2)
 {
-	return user_lock(id1, id2, WRITE_LOCK);
+	return user_lock(id1, id2, ExclusiveLock);
 }
 
 
 int
-user_write_unlock(unsigned int id1, unsigned int id2)
+user_write_unlock(uint32 id1, uint32 id2)
 {
-	return user_unlock(id1, id2, WRITE_LOCK);
+	return user_unlock(id1, id2, ExclusiveLock);
 }
 
 int
 user_write_lock_oid(Oid oid)
 {
-	return user_lock(0, oid, WRITE_LOCK);
+	return user_lock(0, oid, ExclusiveLock);
 }
 
 int
 user_write_unlock_oid(Oid oid)
 {
-	return user_unlock(0, oid, WRITE_LOCK);
+	return user_unlock(0, oid, ExclusiveLock);
 }
 
 int
diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index 8693231a8c65ec3878180f927ff8a57ddaba76af..37b7b053ee8c29c0365e46ffa62639385a36f396 100644
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lock.h,v 1.29 1999/05/29 06:14:42 vadim Exp $
+ * $Id: lock.h,v 1.30 1999/06/01 09:35:39 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -61,14 +61,19 @@ typedef int LOCKMETHOD;
 
 typedef struct LTAG
 {
-	Oid			relId;
-	Oid			dbId;
+	Oid				relId;
+	Oid				dbId;
 	union
 	{
-		BlockNumber blkno;
-		TransactionId xid;
-	}			objId;
-	uint16		lockmethod;		/* needed by user locks */
+		BlockNumber		blkno;
+		TransactionId	xid;
+	}				objId;
+	/* 
+	 * offnum should be part of objId.tupleId above, but would increase 
+	 * sizeof(LOCKTAG) and so moved here; currently used by userlocks only.
+	 */
+	OffsetNumber	offnum;
+	uint16			lockmethod;		/* needed by userlocks */
 } LOCKTAG;
 
 #define TAGSIZE (sizeof(LOCKTAG))