diff --git a/Gemfile b/Gemfile
index 970894a..93d2c53 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-gem 'cayman'
+gem 'Cayman'
 gem "addressable", ">= 2.8.0"
 gem "kramdown", ">= 2.3.1"
 source 'https://rubygems.org'