diff --git a/buildspec-unittests.yml b/buildspec-unittests.yml
index 62e69ac50e..3b2d17d9db 100644
--- a/buildspec-unittests.yml
+++ b/buildspec-unittests.yml
@@ -7,7 +7,7 @@ phases:
       - TOX_PARALLEL_NO_SPINNER=1
       - PY_COLORS=0
       - start_time=`date +%s`
-      - tox -e flake8,pylint,twine,black-check --parallel all
+      - tox -e flake8,pylint,twine,black-check
       - ./ci-scripts/displaytime.sh 'flake8,pylint,twine,black-check' $start_time
 
       - start_time=`date +%s`