diff --git a/Dockerfile b/Dockerfile
index ac2ae14f..49c5938c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:2.3.4
+FROM ruby:2.4.0
 
 # app dependencies
 RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs
diff --git a/Dockerfile.dev b/Dockerfile.dev
index 90241e0a..9396497b 100644
--- a/Dockerfile.dev
+++ b/Dockerfile.dev
@@ -1,4 +1,4 @@
-FROM ruby:2.3.4
+FROM ruby:2.4.0
 
 # app dependencies
 RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs