diff --git a/linguist.gemspec b/linguist.gemspec
index c442f6f8..d9820324 100644
--- a/linguist.gemspec
+++ b/linguist.gemspec
@@ -2,4 +2,6 @@ Gem::Specification.new do |s|
   s.name    = 'linguist'
   s.version = '0.0.1'
   s.summary = "GitHub Language detection"
+
+  s.add_dependency 'mime-types'
 end