killbill-stripe.gemspec in killbill-stripe-4.0.0 vs killbill-stripe.gemspec in killbill-stripe-4.1.0

@@ -32,10 +32,11 @@
     s.add_dependency 'activerecord-jdbc-adapter', '~> 1.3', '< 1.5'
     s.add_dependency 'jruby-openssl', '~> 0.9.7'
   end
   s.add_dependency 'actionpack', '~> 4.1.0'
   s.add_dependency 'actionview', '~> 4.1.0'
-  s.add_dependency 'activemerchant', '~> 1.48.0'
+  # 1.56.0 and above requires Ruby 2.0
+  s.add_dependency 'activemerchant', '~> 1.55.0'
   s.add_dependency 'offsite_payments', '~> 2.1.0'
   s.add_dependency 'monetize', '~> 1.1.0'
   s.add_dependency 'money', '~> 6.5.1'
 
   s.add_development_dependency 'jbundler', '~> 0.9.2'