diff --git a/.ruby-version b/.ruby-version
index 437459c..8e8299d 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.5.0
+2.4.2
diff --git a/.tool-versions b/.tool-versions
index 0531904..dff7248 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1 +1 @@
-ruby 2.5.0
+ruby 2.4.2
diff --git a/Gemfile b/Gemfile
index adf602a..0537423 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,5 @@
 source "https://rubygems.org"
+ruby "2.4.2"
 
 gem "rake"