diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index f595bce31b..84ff4e8c67 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -1871,17 +1871,20 @@ RemoveFromWaitQueue(PGPROC *proc, uint32 hashcode)
 	LOCK	   *waitLock = proc->waitLock;
 	PROCLOCK   *proclock = proc->waitProcLock;
 	LOCKMODE	lockmode = proc->waitLockMode;
-	LOCKMETHODID lockmethodid = LOCK_LOCKMETHOD(*waitLock);
+	LOCKMETHODID lockmethodid;
 
 	/* Make sure proc is waiting */
 	Assert(proc->waitStatus == PROC_WAIT_STATUS_WAITING);
 	Assert(proc->links.next != NULL);
 	Assert(waitLock);
 	Assert(!dclist_is_empty(&waitLock->waitProcs));
+
+	/* Make sure proc is waiting with a valid lock method */
+	lockmethodid = LOCK_LOCKMETHOD(*waitLock);
 	Assert(0 < lockmethodid && lockmethodid < lengthof(LockMethods));
 
 	/* Remove proc from lock's wait queue */
-	dclist_delete_from(&waitLock->waitProcs, &proc->links);
+	dclist_delete_from_thoroughly(&waitLock->waitProcs, &proc->links);
 
 	/* Undo increments of request counts by waiting process */
 	Assert(waitLock->nRequested > 0);