diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
index 54baeef258..6b84b6e434 100644
--- a/.github/workflows/build-and-test.yml
+++ b/.github/workflows/build-and-test.yml
@@ -49,7 +49,7 @@ jobs:
       - name: "Install test runner dependencies"
         run: |
           set -xe
-          python -m pip install --upgrade pip setuptools wheel 'tox<4' tox-gh-actions coverage virtualenv snmpsim
+          python -m pip install --upgrade pip setuptools wheel 'tox<4' tox-gh-actions coverage virtualenv snmpsim 'pyasn1<0.5.0'
           sudo apt-get install -y nbtscan
 
       # virtualenv seems to currently be embedding a broken version of
diff --git a/tests/docker/Dockerfile b/tests/docker/Dockerfile
index 304cfcd791..09e1dbabb5 100644
--- a/tests/docker/Dockerfile
+++ b/tests/docker/Dockerfile
@@ -65,7 +65,7 @@ RUN cd /tmp && \
     mv chromedriver /usr/local/bin/
 
 # Install our primary test runner
-RUN python3.7 -m pip install 'tox<4' snmpsim virtualenv
+RUN python3.7 -m pip install 'tox<4' snmpsim 'pyasn1<0.5.0' virtualenv
 
 # Add a build user
 ENV USER build