diff --git a/Gemfile b/Gemfile
old mode 100755
new mode 100644
index 5f69527..f6c89fa
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'http://rubygems.org'
 ruby '2.1.2'
  
 gem 'tilt', '~> 1.4.1'
-gem "sinatra"
+gem "sinatra", ">= 4.1.0"
 gem "rack-flash3"
 gem "haml"
 gem "json"