diff --git a/tests/queries/0_stateless/01509_check_many_parallel_quorum_inserts_long.sh b/tests/queries/0_stateless/01509_check_many_parallel_quorum_inserts_long.sh
index 6533eeb12f5..a6f151d0f6f 100755
--- a/tests/queries/0_stateless/01509_check_many_parallel_quorum_inserts_long.sh
+++ b/tests/queries/0_stateless/01509_check_many_parallel_quorum_inserts_long.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Tags: long, no-replicated-database
+# Tags: long, no-replicated-database, no-parallel
 # Tag no-replicated-database: Fails due to additional replicas or shards
 
 set -e
diff --git a/tests/queries/0_stateless/02033_join_engine_deadlock_long.sh b/tests/queries/0_stateless/02033_join_engine_deadlock_long.sh
index 2a887cbbcae..1e670b72fe7 100755
--- a/tests/queries/0_stateless/02033_join_engine_deadlock_long.sh
+++ b/tests/queries/0_stateless/02033_join_engine_deadlock_long.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Tags: long, deadlock
+# Tags: long, deadlock, no-parallel
 
 CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
 # shellcheck source=../shell_config.sh