diff --git a/Dockerfile b/Dockerfile
index 027766e6..6e7c2354 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -72,6 +72,7 @@ COPY work/roi-drawing.ipynb /home/$NB_USER/open_me.ipynb
 
 USER root
 RUN chown -R $NB_USER /home/$NB_USER/.ipython && chmod 700 /home/$NB_USER/.ipython
+RUN mkdir -p /opt/ext/python
 USER $NB_USER
 
 # And mark it as the entrypoint
diff --git a/docker-compose.yml b/docker-compose.yml
index 4e353c30..4ee856fc 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -5,6 +5,8 @@ services:
       ports:
          - "8888:8888"
       volumes:
-         - ${PWD}/hcpannot:/opt/conda/lib/python3.9/hcpannot
+         - ${PWD}/hcpannot:/opt/ext/python/hcpannot
          - ${PWD}/save:/save
          - ${PWD}/.git:/home/jovyan/.extgit
+      environment:
+         - PYTHONPATH=/opt/ext/python