diff --git a/active_model_serializers.gemspec b/active_model_serializers.gemspec
index d3b85d55..3ae91fc1 100644
--- a/active_model_serializers.gemspec
+++ b/active_model_serializers.gemspec
@@ -18,9 +18,9 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "activesupport", ">= 4.0"
-  spec.add_dependency "rails", ">= 4.0"
+  spec.add_dependency "activemodel", ">= 4.0"
 
+  spec.add_development_dependency "rails", ">= 4.0"
   spec.add_development_dependency "bundler", "~> 1.6"
   spec.add_development_dependency "rake"
 end