diff --git a/.circleci/config.yml b/.circleci/config.yml
index 991563754..607782a97 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -22,7 +22,8 @@ jobs:
       - run: make assets
 
       # Uruchamiaj na lokalnym firefoxie używając jednego CPU
-      - run: pytest -n 2 --cov=src --splinter-webdriver=firefox  --nginx-host=localhost --liveserver=localhost 
+      - run: pytest -n 2 --cov=src --splinter-webdriver=firefox  --nginx-host=localhost --liveserver=localhost -m "not serial"
+      - run: pytest -n 0 --splinter-webdriver=firefox  --nginx-host=localhost --liveserver=localhost -m "serial"
 
       # Testy JavaScript
       - run: make js-tests
diff --git a/Makefile b/Makefile
index 943294e73..fd4708241 100644
--- a/Makefile
+++ b/Makefile
@@ -71,7 +71,8 @@ jenkins:
 	pipenv install -d
 	make assets
 
-	pytest --ds=django_bpp.settings.local -n6 --splinter-webdriver=firefox --nginx-host=localhost --liveserver=localhost --create-db --maxfail=20
+	pytest -m "not serial" --ds=django_bpp.settings.local -n6 --splinter-webdriver=firefox --nginx-host=localhost --liveserver=localhost --create-db --maxfail=20
+	pytest -m "serial" --ds=django_bpp.settings.local -n0 --splinter-webdriver=firefox --nginx-host=localhost --liveserver=localhost --create-db --maxfail=20
 
 	yarn
 	make js-tests
diff --git a/Pipfile b/Pipfile
index e8c3c8be0..dd8b742a3 100644
--- a/Pipfile
+++ b/Pipfile
@@ -79,7 +79,7 @@ sphinx-autobuild = "==0.7.1"
 pdbpp = "==0.9.1"
 coveralls = "==1.10.0"
 psutil = "==5.4.5"
-pytest = "*"
+pytest = "==5.3.2"
 pytest-django = "*"
 pytest-cov = "*"
 pytest-localserver = "*"
diff --git a/src/bpp/tests/tests_legacy/test_commands.py b/src/bpp/tests/tests_legacy/test_commands.py
index 62bc1e73c..53d828644 100644
--- a/src/bpp/tests/tests_legacy/test_commands.py
+++ b/src/bpp/tests/tests_legacy/test_commands.py
@@ -1,3 +1,4 @@
+import pytest
 from model_mommy import mommy
 from django.core.management import call_command
 
@@ -21,6 +22,7 @@ def test_afiliacja(self):
         afiliacja(d1, kw)
         self.assertEqual(kw['recenzowana'], False)
 
+    @pytest.mark.serial
     def test_rebuild_cache(self):
         mommy.make(Wydawnictwo_Ciagle)
-        call_command("rebuild_cache")
\ No newline at end of file
+        call_command("rebuild_cache")