diff --git a/docker/Dockerfile_ubuntu_18.04 b/docker/Dockerfile_ubuntu_18.04
index 309a6218da3605e7fb5563374580c20c171ec68c..307cdc2638c1f6111d8ceeffe2e7096905cbf6c9 100644
--- a/docker/Dockerfile_ubuntu_18.04
+++ b/docker/Dockerfile_ubuntu_18.04
@@ -16,6 +16,7 @@ RUN apt-get update && \
         python3-sphinx-gallery \
         python3-matplotlib \
         python3-pil \
+        python3-cvxopt \
         && \
     apt-get clean
 RUN apt-get install -y --no-install-recommends locales && \