diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c
index 5fd47689dd2..2744170f91b 100644
--- a/src/backend/replication/syncrep.c
+++ b/src/backend/replication/syncrep.c
@@ -295,6 +295,7 @@ SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
 	 * holding SyncRepLock, because any walsenders will ignore us anyway when
 	 * we're not on the queue.
 	 */
+	pg_read_barrier();
 	Assert(SHMQueueIsDetached(&(MyProc->syncRepLinks)));
 	MyProc->syncRepState = SYNC_REP_NOT_WAITING;
 	MyProc->waitLSN = 0;
@@ -1002,15 +1003,17 @@ SyncRepWakeQueue(bool all, int mode)
 									   offsetof(PGPROC, syncRepLinks));
 
 		/*
-		 * Set state to complete; see SyncRepWaitForLSN() for discussion of
-		 * the various states.
+		 * Remove thisproc from queue.
 		 */
-		thisproc->syncRepState = SYNC_REP_WAIT_COMPLETE;
+		SHMQueueDelete(&(thisproc->syncRepLinks));
+
+		pg_write_barrier();
 
 		/*
-		 * Remove thisproc from queue.
+		 * Set state to complete; see SyncRepWaitForLSN() for discussion of
+		 * the various states.
 		 */
-		SHMQueueDelete(&(thisproc->syncRepLinks));
+		thisproc->syncRepState = SYNC_REP_WAIT_COMPLETE;
 
 		/*
 		 * Wake only when we have set state and removed from queue.