diff --git a/Dockerfile b/Dockerfile
index 444785f..fd978b8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -19,10 +19,11 @@
     cd /opt/wally && \
     python3.6 -m pip install wheel && \
     python3.6 -m pip install -r requirements.txt && \
-    ln -s scripts/wally /usr/bin && \
+    python3.6 -m pip install -U cryptography && \
+    ln -s /opt/wally/scripts/wally /usr/bin && \
     chmod a+x /opt/wally/scripts/wally
 
-RUN
+RUN apt purge -y python3-dev build-essential && apt -y autoremove
 
 ENV PYTHONPATH /opt/cephlib:/opt/xmlbuilder3:/opt/agent:/opt/wally