diff --git a/.ruby-version b/.ruby-version
index 2bf1c1c..35cee72 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.3.1
+2.4.3
diff --git a/.tool-versions b/.tool-versions
new file mode 100644
index 0000000..5cfccd9
--- /dev/null
+++ b/.tool-versions
@@ -0,0 +1 @@
+ruby 2.4.3