diff --git a/Dockerfile b/Dockerfile
index 1e46a62f95..31e863d8a0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,7 +14,7 @@ COPY NOTICE                                 /NOTICE
 COPY npm_licenses.tar.bz2                   /npm_licenses.tar.bz2
 
 WORKDIR /prometheus
-RUN chown -R nobody:nobody /etc/prometheus /prometheus
+RUN chown -R nobody:nobody /etc/prometheus /prometheus && chmod g+w /prometheus
 
 USER       nobody
 EXPOSE     9090