diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 4c3a6a44f43..34ac280c1b8 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -3459,6 +3459,8 @@ doRetry(CState *st, pg_time_usec_t *now)
 static int
 discardUntilSync(CState *st)
 {
+	bool		received_sync = false;
+
 	/* send a sync */
 	if (!PQpipelineSync(st->con))
 	{
@@ -3473,10 +3475,16 @@ discardUntilSync(CState *st)
 		PGresult   *res = PQgetResult(st->con);
 
 		if (PQresultStatus(res) == PGRES_PIPELINE_SYNC)
+			received_sync = true;
+		else if (received_sync)
 		{
-			PQclear(res);
-			res = PQgetResult(st->con);
+			/*
+			 * PGRES_PIPELINE_SYNC must be followed by another
+			 * PGRES_PIPELINE_SYNC or NULL; otherwise, assert failure.
+			 */
 			Assert(res == NULL);
+
+			PQclear(res);
 			break;
 		}
 		PQclear(res);