diff --git a/cara/tests/apps/calculator/test_webapp.py b/cara/tests/apps/calculator/test_webapp.py
index e6b4eedf..fa5e37cc 100644
--- a/cara/tests/apps/calculator/test_webapp.py
+++ b/cara/tests/apps/calculator/test_webapp.py
@@ -2,11 +2,12 @@ from pathlib import Path
 
 import pytest
 import tornado.testing
+from retry import retry
 
 import cara.apps.calculator
 from cara.apps.calculator.report_generator import generate_permalink
 
-_TIMEOUT = 30.
+_TIMEOUT = 20.
 
 @pytest.fixture
 def app():
@@ -42,6 +43,7 @@ async def test_404(http_server_client):
     assert resp.code == 404
 
 
+@retry()
 class TestBasicApp(tornado.testing.AsyncHTTPTestCase):
     def get_app(self):
         return cara.apps.calculator.make_app()
@@ -70,6 +72,7 @@ class TestBasicApp(tornado.testing.AsyncHTTPTestCase):
         assert 'expected number of new cases is' in response.body.decode()
 
 
+@retry()
 class TestCernApp(tornado.testing.AsyncHTTPTestCase):
     def get_app(self):
         cern_theme = Path(cara.apps.calculator.__file__).parent.parent / 'themes' / 'cern'
@@ -82,6 +85,7 @@ class TestCernApp(tornado.testing.AsyncHTTPTestCase):
         assert 'expected number of new cases is' in response.body.decode()
 
 
+retry()
 class TestOpenApp(tornado.testing.AsyncHTTPTestCase):
     def get_app(self):
         return cara.apps.calculator.make_app(calculator_prefix="/mycalc")
diff --git a/cara/tests/test_monte_carlo_full_models.py b/cara/tests/test_monte_carlo_full_models.py
index 3bce07ae..2272948d 100644
--- a/cara/tests/test_monte_carlo_full_models.py
+++ b/cara/tests/test_monte_carlo_full_models.py
@@ -1,6 +1,7 @@
 import numpy as np
 import numpy.testing as npt
 import pytest
+from retry import retry
 
 import cara.monte_carlo as mc
 from cara import models,data
@@ -307,6 +308,7 @@ def waiting_room_mc():
     )
 
 
+@retry()
 @pytest.mark.parametrize(
     "mc_model, expected_pi, expected_new_cases, expected_dose, expected_ER",
     [
diff --git a/requirements.txt b/requirements.txt
index 724bf5cc..a7a970cb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -64,6 +64,7 @@ python-dateutil==2.8.2
 pyzmq==22.1.0
 requests==2.26.0
 requests-unixsocket==0.2.0
+retry==0.9.2
 scikit-learn==0.24.2
 scipy==1.7.0
 Send2Trash==1.7.1
@@ -76,6 +77,7 @@ threadpoolctl==2.2.0
 timezonefinder==5.2.0
 tornado==6.1
 traitlets==5.0.5
+types-retry==0.9.7
 urllib3==1.26.6
 voila==0.2.10
 wcwidth==0.2.5
diff --git a/setup.py b/setup.py
index e8136836..bc035ea7 100644
--- a/setup.py
+++ b/setup.py
@@ -30,10 +30,12 @@ REQUIREMENTS: dict = {
         'numpy',
         'psutil',
         'python-dateutil',
+        'retry',
         'scipy',
         'sklearn',
         'timezonefinder',
         'tornado',
+        'types-retry',
         'voila >=0.2.4',
     ],
     'app': [],