diff --git a/lr_common_styles.gemspec b/lr_common_styles.gemspec
index 2587524..4c34d18 100644
--- a/lr_common_styles.gemspec
+++ b/lr_common_styles.gemspec
@@ -35,7 +35,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'rails', '~> 5.2.4'
   s.add_dependency 'sass-rails', '~> 5.0.4'
 
-  s.add_development_dependency 'minitest-rails'
-  s.add_development_dependency 'mocha'
-  s.add_development_dependency 'rails_real_favicon'
+  s.add_development_dependency 'minitest-rails', '~> 5.2.0'
+  s.add_development_dependency 'mocha', '~> 2.0.0'
+  s.add_development_dependency 'rails_real_favicon', '~> 0.1.0'
 end