diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 723f513d8b..a093ae0656 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -555,7 +555,7 @@ WalReceiverMain(void)
 
 						/*
 						 * We didn't receive anything new, for half of
-						 * receiver replication timeout. Ping the server.
+						 * WAL receiver timeout. Ping the server.
 						 */
 						if (!ping_sent)
 						{
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index fe0d368a35..0b601a3821 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -2237,12 +2237,12 @@ WalSndCheckTimeOut(void)
 	if (wal_sender_timeout > 0 && last_processing >= timeout)
 	{
 		/*
-		 * Since typically expiration of replication timeout means
+		 * Since typically expiration of WAL sender timeout means
 		 * communication problem, we don't send the error message to the
 		 * standby.
 		 */
 		ereport(COMMERROR,
-				(errmsg("terminating walsender process due to replication timeout")));
+				(errmsg("terminating walsender process due to WAL sender timeout")));
 
 		WalSndShutdown();
 	}
@@ -2335,7 +2335,7 @@ WalSndLoop(WalSndSendDataCallback send_data)
 				WalSndDone(send_data);
 		}
 
-		/* Check for replication timeout. */
+		/* Check for WAL sender timeout. */
 		WalSndCheckTimeOut();
 
 		/* Send keepalive if the time has come */