diff --git a/firefly.gemspec b/firefly.gemspec
index 0cc7731..ca693ca 100644
--- a/firefly.gemspec
+++ b/firefly.gemspec
@@ -14,9 +14,9 @@ Gem::Specification.new do |s|
 
   s.files = Dir["{app,config,db,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.rdoc"]
 
-  s.add_dependency "rails", "~> 4.0.0"
-  s.add_dependency 'sass-rails', '~> 4.0.0'
-  s.add_dependency 'haml-rails', '~> 0.4'
+  s.add_dependency "rails", ">= 4.0.0"
+  s.add_dependency 'sass-rails', '>= 4.0.0'
+  s.add_dependency 'haml-rails', '>= 0.4'
   s.add_development_dependency 'rspec-rails'
   s.add_development_dependency 'capybara'
   s.add_development_dependency 'capybara-webkit'