diff --git a/docker/bionic/Dockerfile b/docker/bionic/Dockerfile
index 961a0df..b5e7e0a 100644
--- a/docker/bionic/Dockerfile
+++ b/docker/bionic/Dockerfile
@@ -56,6 +56,10 @@ RUN apt-get install -yq --no-install-suggests --no-install-recommends \
 RUN apt-get install -yq --no-install-suggests --no-install-recommends \
     python3.7 python3.7-dev
 
+# tests
+RUN apt-get install -yq --no-install-suggests --no-install-recommends \
+    shunit2
+
 # .travis.yml
 RUN apt-get install -yq --no-install-suggests --no-install-recommends \
     build-essential libcap-dev tor