diff --git a/Dockerfile b/Dockerfile
index 42b0efa..6c685b2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@ ARG ALPINE_VERSION
 MAINTAINER f <f@sutty.nl>
 ENV RAILS_ENV production
 
-RUN addgroup -g 82 -S www-data
+RUN getent group 82 || addgroup -g 82 -S www-data
 RUN adduser -s /bin/sh -G www-data -h /srv -D rails
 RUN install -dm 750 -o rails -g www-data /srv