diff --git a/Dockerfile b/Dockerfile
index 1d6dba4..3229b18 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,3 +1,3 @@
 FROM etherpad/etherpad:1.8.6
 
-npm install prompt_for_name ep_comments_page
\ No newline at end of file
+RUN npm install prompt_for_name ep_comments_page
\ No newline at end of file