diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c
index f9c12e603b..c9bb3e987d 100644
--- a/src/backend/storage/ipc/standby.c
+++ b/src/backend/storage/ipc/standby.c
@@ -661,8 +661,7 @@ StandbyAcquireAccessExclusiveLock(TransactionId xid, Oid dbOid, Oid relOid)
 
 	SET_LOCKTAG_RELATION(locktag, newlock->dbOid, newlock->relOid);
 
-	(void) LockAcquireExtended(&locktag, AccessExclusiveLock, true, false,
-							   false, NULL);
+	(void) LockAcquire(&locktag, AccessExclusiveLock, true, false);
 }
 
 static void
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 58d1f32cf3..831ae62525 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -693,11 +693,13 @@ LockAcquire(const LOCKTAG *locktag,
 /*
  * LockAcquireExtended - allows us to specify additional options
  *
- * reportMemoryError specifies whether a lock request that fills the
- * lock table should generate an ERROR or not. This allows a priority
- * caller to note that the lock table is full and then begin taking
- * extreme action to reduce the number of other lock holders before
- * retrying the action.
+ * reportMemoryError specifies whether a lock request that fills the lock
+ * table should generate an ERROR or not.  Passing "false" allows the caller
+ * to attempt to recover from lock-table-full situations, perhaps by forcibly
+ * cancelling other lock holders and then retrying.  Note, however, that the
+ * return code for that is LOCKACQUIRE_NOT_AVAIL, so that it's unsafe to use
+ * in combination with dontWait = true, as the cause of failure couldn't be
+ * distinguished.
  *
  * If locallockp isn't NULL, *locallockp receives a pointer to the LOCALLOCK
  * table entry if a lock is successfully acquired, or NULL if not.