diff --git a/actionmailer/actionmailer.gemspec b/actionmailer/actionmailer.gemspec
index b958885808..1cbcb3d729 100644
--- a/actionmailer/actionmailer.gemspec
+++ b/actionmailer/actionmailer.gemspec
@@ -17,5 +17,5 @@ Gem::Specification.new do |s|
   s.requirements << 'none'
 
   s.add_dependency('actionpack',  version)
-  s.add_dependency('mail',        '~> 2.3.3')
+  s.add_dependency('mail',        '~> 2.5')
 end