diff --git a/Dockerfile.ruby-2.3 b/Dockerfile.ruby-2.3
index 79afc2f..c056b95 100644
--- a/Dockerfile.ruby-2.3
+++ b/Dockerfile.ruby-2.3
@@ -1,4 +1,4 @@
-FROM ruby:2.3
+FROM ruby:2.3.1
 
 ENV PACKAGES="git-core" \
 	LC_ALL=en_US.UTF-8