diff --git a/.github/dodona-image.dockerfile b/.github/dodona-image.dockerfile
index 2e571a00..d9abcfdf 100644
--- a/.github/dodona-image.dockerfile
+++ b/.github/dodona-image.dockerfile
@@ -6,7 +6,7 @@ USER root
 WORKDIR /
 
 # Install some additional dependencies needed for testing.
-RUN pip install --no-cache-dir --upgrade pytest pytest-mock pytest-xdist
+RUN pip install --no-cache-dir --upgrade pytest pytest-mock pytest-xdist jinja2 marko
 
 # The source of the judge is available in TESTED_SOURCE.
-CMD pytest -n auto ${TESTED_SOURCE}/tests/
+CMD pytest -x -n auto ${TESTED_SOURCE}/tests/