diff --git a/actionmailer/actionmailer.gemspec b/actionmailer/actionmailer.gemspec
index 29b5813785..2ae85f8b57 100644
--- a/actionmailer/actionmailer.gemspec
+++ b/actionmailer/actionmailer.gemspec
@@ -20,5 +20,5 @@ Gem::Specification.new do |s|
   s.has_rdoc = true
 
   s.add_dependency('actionpack',  version)
-  s.add_dependency('mail',        '~> 2.2.9')
+  s.add_dependency('mail',        '~> 2.2.15')
 end