diff --git a/Gemfile b/Gemfile
index 7092e2c..55e11b9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ gem "jquery-rails", "~> 3.1.4"
 gem "coderay", "~> 1.1.0"
 gem "builder", ">= 3.0.4"
 gem "request_store", "1.0.5"
-gem "mime-types"
+gem "mime-types", (RUBY_VERSION >= "2.0" ? "~> 3.0" : "~> 2.99")
 gem "protected_attributes"
 gem "actionpack-action_caching"
 gem "actionpack-xml_parser"