diff --git a/Dockerfile b/Dockerfile
index 024ed61e0..10331fd7a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
-# Use Ruby 2.3.8 as base image
-FROM ruby:2.3.8
+# Use Ruby 2.4.9 as base image
+FROM ruby:2.4.9
 
 ENV DEBIAN_FRONTEND noninteractive