diff --git a/Dockerfile b/Dockerfile
index c4b3753..bcc9815 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 FROM  python:3.7.4-alpine3.10
 
-RUN pip install plantuml
+RUN pip install plantuml==0.3.0
 
 ENTRYPOINT for f in **/*.plantuml; do echo $f; python -m plantuml $f; done