diff --git a/ar-octopus.gemspec b/ar-octopus.gemspec
index 7f2023c4..84eb1f6b 100644
--- a/ar-octopus.gemspec
+++ b/ar-octopus.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'activesupport', '>= 4.0.0', "< 5.2.0"
 
   s.add_development_dependency 'appraisal', '>= 0.3.8'
-  s.add_development_dependency 'mysql2', '>= 0.4', "< 0.5"
+  s.add_development_dependency 'mysql2', '>= 0.4', '< 0.6'
   s.add_development_dependency 'pg', '~> 0.18'
   s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec', '>= 3'