diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c
index ad213fc454..5ab5e95fa9 100644
--- a/src/backend/replication/syncrep.c
+++ b/src/backend/replication/syncrep.c
@@ -409,15 +409,23 @@ void
 SyncRepReleaseWaiters(void)
 {
 	volatile WalSndCtlData *walsndctl = WalSndCtl;
+	WalSnd	   *walsnd = MyWalSnd;
 	XLogRecPtr	writePtr;
 	XLogRecPtr	flushPtr;
 	XLogRecPtr	applyPtr;
+	XLogRecPtr	flush;
+	WalSndState	state;
 	bool		got_recptr;
 	bool		am_sync;
 	int			numwrite = 0;
 	int			numflush = 0;
 	int			numapply = 0;
 
+	SpinLockAcquire(&walsnd->mutex);
+	flush = walsnd->flush;
+	state = walsnd->state;
+	SpinLockRelease(&walsnd->mutex);
+
 	/*
 	 * If this WALSender is serving a standby that is not on the list of
 	 * potential sync standbys then we have nothing to do. If we are still
@@ -425,8 +433,8 @@ SyncRepReleaseWaiters(void)
 	 * still invalid, then leave quickly also.
 	 */
 	if (MyWalSnd->sync_standby_priority == 0 ||
-		MyWalSnd->state < WALSNDSTATE_STREAMING ||
-		XLogRecPtrIsInvalid(MyWalSnd->flush))
+		state < WALSNDSTATE_STREAMING ||
+		XLogRecPtrIsInvalid(flush))
 	{
 		announce_next_takeover = true;
 		return;
@@ -711,14 +719,24 @@ SyncRepGetSyncStandbysQuorum(bool *am_sync)
 
 	for (i = 0; i < max_wal_senders; i++)
 	{
+		XLogRecPtr	flush;
+		WalSndState	state;
+		int			pid;
+
 		walsnd = &WalSndCtl->walsnds[i];
 
+		SpinLockAcquire(&walsnd->mutex);
+		pid = walsnd->pid;
+		flush = walsnd->flush;
+		state = walsnd->state;
+		SpinLockRelease(&walsnd->mutex);
+
 		/* Must be active */
-		if (walsnd->pid == 0)
+		if (pid == 0)
 			continue;
 
 		/* Must be streaming */
-		if (walsnd->state != WALSNDSTATE_STREAMING)
+		if (state != WALSNDSTATE_STREAMING)
 			continue;
 
 		/* Must be synchronous */
@@ -726,7 +744,7 @@ SyncRepGetSyncStandbysQuorum(bool *am_sync)
 			continue;
 
 		/* Must have a valid flush position */
-		if (XLogRecPtrIsInvalid(walsnd->flush))
+		if (XLogRecPtrIsInvalid(flush))
 			continue;
 
 		/*
@@ -780,14 +798,24 @@ SyncRepGetSyncStandbysPriority(bool *am_sync)
 	 */
 	for (i = 0; i < max_wal_senders; i++)
 	{
+		XLogRecPtr	flush;
+		WalSndState	state;
+		int			pid;
+
 		walsnd = &WalSndCtl->walsnds[i];
 
+		SpinLockAcquire(&walsnd->mutex);
+		pid = walsnd->pid;
+		flush = walsnd->flush;
+		state = walsnd->state;
+		SpinLockRelease(&walsnd->mutex);
+
 		/* Must be active */
-		if (walsnd->pid == 0)
+		if (pid == 0)
 			continue;
 
 		/* Must be streaming */
-		if (walsnd->state != WALSNDSTATE_STREAMING)
+		if (state != WALSNDSTATE_STREAMING)
 			continue;
 
 		/* Must be synchronous */
@@ -796,7 +824,7 @@ SyncRepGetSyncStandbysPriority(bool *am_sync)
 			continue;
 
 		/* Must have a valid flush position */
-		if (XLogRecPtrIsInvalid(walsnd->flush))
+		if (XLogRecPtrIsInvalid(flush))
 			continue;
 
 		/*
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 49cce38880..a04be8039d 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -2874,10 +2874,12 @@ WalSndRqstFileReload(void)
 	{
 		WalSnd	   *walsnd = &WalSndCtl->walsnds[i];
 
+		SpinLockAcquire(&walsnd->mutex);
 		if (walsnd->pid == 0)
+		{
+			SpinLockRelease(&walsnd->mutex);
 			continue;
-
-		SpinLockAcquire(&walsnd->mutex);
+		}
 		walsnd->needreload = true;
 		SpinLockRelease(&walsnd->mutex);
 	}
@@ -3190,14 +3192,18 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 		TimeOffset	flushLag;
 		TimeOffset	applyLag;
 		int			priority;
+		int			pid;
 		WalSndState state;
 		Datum		values[PG_STAT_GET_WAL_SENDERS_COLS];
 		bool		nulls[PG_STAT_GET_WAL_SENDERS_COLS];
 
+		SpinLockAcquire(&walsnd->mutex);
 		if (walsnd->pid == 0)
+		{
+			SpinLockRelease(&walsnd->mutex);
 			continue;
-
-		SpinLockAcquire(&walsnd->mutex);
+		}
+		pid = walsnd->pid;
 		sentPtr = walsnd->sentPtr;
 		state = walsnd->state;
 		write = walsnd->write;
@@ -3210,7 +3216,7 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 		SpinLockRelease(&walsnd->mutex);
 
 		memset(nulls, 0, sizeof(nulls));
-		values[0] = Int32GetDatum(walsnd->pid);
+		values[0] = Int32GetDatum(pid);
 
 		if (!superuser())
 		{