diff --git a/production.Dockerfile b/production.Dockerfile
index 051448f..7c8ef0a 100644
--- a/production.Dockerfile
+++ b/production.Dockerfile
@@ -10,7 +10,7 @@ WORKDIR /rails
 ENV RAILS_ENV="production" \
     BUNDLE_DEPLOYMENT="1" \
     BUNDLE_JOBS="4" \
-    BUNDLE_WITHOUT="development,test" \
+    BUNDLE_WITHOUT="development:test" \
     BUNDLE_PATH="/usr/local/bundle"