diff --git a/sensu-plugins-mailer.gemspec b/sensu-plugins-mailer.gemspec
index 75426c4..a30b956 100644
--- a/sensu-plugins-mailer.gemspec
+++ b/sensu-plugins-mailer.gemspec
@@ -29,7 +29,7 @@ Gem::Specification.new do |s|
 
   s.add_runtime_dependency 'aws-ses',           '0.6.0'
   s.add_runtime_dependency 'mail',              '2.6.3'
-  s.add_runtime_dependency 'mailgun-ruby',      '1.0.3'
+  s.add_runtime_dependency 'mailgun-ruby',      '1.2.0'
   s.add_runtime_dependency 'sensu-plugin',      '~> 4.0'
   s.add_runtime_dependency 'erubis',            '2.7.0'
   s.add_runtime_dependency 'ruby-ntlm',         '0.0.4'