diff --git a/Dockerfile b/Dockerfile
index a727571..5b45100 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,4 +14,5 @@ COPY entrypoint.sh /sbin/entrypoint.sh
 RUN chmod 755 /sbin/entrypoint.sh
 
 EXPOSE 3128/tcp
+VOLUME $SQUID_CACHE_DIR
 ENTRYPOINT ["/sbin/entrypoint.sh"]