diff --git a/Dockerfile b/Dockerfile
index 6e3a262..4ecdd39 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,7 +16,7 @@ COPY www-swagg.pl .
 # Dependency time
 RUN apt-get update
 RUN apt-get -y upgrade
-RUN apt-get -y install fortune-mod ruby
+RUN apt-get -y install fortune-mod ruby-dev
 RUN cpanm --installdeps .
 RUN gem install cgi