diff --git a/Gemfile b/Gemfile
index b2a59e6..2be5041 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,7 @@ source 'https://rubygems.org'
 
 group :test do
   gem 'coveralls', require: false
+  gem 'mime-types', '< 3'
 end
 
 gemspec
diff --git a/Gemfile.lock b/Gemfile.lock
index bf9fc33..613c17c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -18,9 +18,7 @@ GEM
     hashie (3.4.3)
     macaddr (1.7.1)
       systemu (~> 2.6.2)
-    mime-types (3.0)
-      mime-types-data (~> 3.2015)
-    mime-types-data (3.2015.1120)
+    mime-types (2.99)
     mini_portile2 (2.0.0)
     multi_json (1.3.7)
     nokogiri (1.6.7.1)
@@ -61,6 +59,7 @@ PLATFORMS
 
 DEPENDENCIES
   coveralls
+  mime-types (< 3)
   omniauth-saml!
   rack-test (~> 0.6)
   rspec (~> 2.8)