diff --git a/attachinary.gemspec b/attachinary.gemspec
index 8a8d8806..1b1272db 100644
--- a/attachinary.gemspec
+++ b/attachinary.gemspec
@@ -16,8 +16,8 @@ Gem::Specification.new do |s|
   s.files = Dir["{app,config,db,lib,vendor}/**/*"] + ["MIT-LICENSE", "Rakefile", "README.md"]
   s.test_files = Dir["test/**/*"]
 
-  s.add_dependency 'rails', '>= 3.2'
-  s.add_dependency 'cloudinary', '~> 1.1.0'
+  s.add_dependency 'rails', '>= 3.2', '< 5.2'
+  s.add_dependency 'cloudinary', '~> 1.8'
 
   s.add_development_dependency 'sqlite3'
   s.add_development_dependency 'rspec-rails'
diff --git a/lib/attachinary/orm/active_record/extension.rb b/lib/attachinary/orm/active_record/extension.rb
index 05946bfc..e8b400ce 100644
--- a/lib/attachinary/orm/active_record/extension.rb
+++ b/lib/attachinary/orm/active_record/extension.rb
@@ -15,10 +15,17 @@ def attachinary_orm_definition(options)
           class_name: '::Attachinary::File',
           conditions: { scope: options[:scope].to_s },
           dependent: :destroy
+      elsif Rails::VERSION::MAJOR > 3 && Rails::VERSION::MAJOR < 5
+        has_many :"#{relation}",
+                 -> { where scope: options[:scope].to_s },
+                 as: :attachinariable,
+                 class_name: '::Attachinary::File',
+                 dependent: :destroy
       else
         has_many :"#{relation}",
           -> { where scope: options[:scope].to_s }, 
           as: :attachinariable,
+          inverse_of: :attachinariable,
           class_name: '::Attachinary::File',
           dependent: :destroy
       end