diff --git a/grape-active_model_serializers.gemspec b/grape-active_model_serializers.gemspec
index f7e1a8b..4ab59fe 100644
--- a/grape-active_model_serializers.gemspec
+++ b/grape-active_model_serializers.gemspec
@@ -24,5 +24,5 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency 'rack-test'
   gem.add_development_dependency 'rake'
   gem.add_development_dependency 'guard-rspec'
-  gem.add_development_dependency 'rubocop'
+  gem.add_development_dependency 'rubocop', '0.41.2'
 end