diff --git a/pickle.gemspec b/pickle.gemspec
index 7cf82e3..b2a8c95 100644
--- a/pickle.gemspec
+++ b/pickle.gemspec
@@ -27,6 +27,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "git"
   s.add_development_dependency "yard"
   s.add_development_dependency "rspec-rails", "~>3.0"
+  s.add_development_dependency "rspec-mocks", ">= 3.12.4"
   s.add_development_dependency "rails", ">= 6.0", "< 8.0"
   s.add_development_dependency "cucumber-rails"
   s.add_development_dependency "factory_bot"