diff --git a/docker/Dockerfile_ubuntu_18.04 b/docker/Dockerfile_ubuntu_18.04
index 3d9445b6b57cc65c47b0110bb32b02a2b1fc5576..4e3bfa76f57ec17ee49037656c60792cbd59fd24 100644
--- a/docker/Dockerfile_ubuntu_18.04
+++ b/docker/Dockerfile_ubuntu_18.04
@@ -19,6 +19,7 @@ RUN apt-get update && \
         python3-matplotlib \
         python3-pil \
         libhdf5-dev \
+        python3-tk \
         git \
         && \
     apt-get clean