diff --git a/Dockerfile.jetty b/Dockerfile.jetty
index 0e68353..f1d939c 100644
--- a/Dockerfile.jetty
+++ b/Dockerfile.jetty
@@ -19,4 +19,6 @@ RUN apt-get update && \
 
 USER jetty
 
+ENV GRAPHVIZ_DOT=/usr/bin/dot
+
 COPY --from=builder /app/target/plantuml.war /var/lib/jetty/webapps/ROOT.war
diff --git a/Dockerfile.tomcat b/Dockerfile.tomcat
index 5274668..d0679ab 100644
--- a/Dockerfile.tomcat
+++ b/Dockerfile.tomcat
@@ -15,5 +15,7 @@ RUN apt-get update && \
     apt-get install -y --no-install-recommends graphviz fonts-wqy-zenhei && \
     apt-get clean
 
+ENV GRAPHVIZ_DOT=/usr/bin/dot
+
 RUN rm -rf /usr/local/tomcat/webapps/ROOT
 COPY --from=builder /app/target/plantuml.war /usr/local/tomcat/webapps/ROOT.war