diff --git a/Dockerfile b/Dockerfile
index adfcd85..086d551 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -37,7 +37,7 @@ RUN pip3 install wheel && pip3 install -U spacy && \
 COPY nlp /usr/local/bin
 COPY spacy_nlp /usr/local/bin
 
-mkdir /input /output
-chmod a+rw /input /output
+RUN mkdir /input /output && \
+    chmod a+rw /input /output
 
 ENTRYPOINT ["nlp"]