diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 2207f119c3..501fee55aa 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -517,8 +517,8 @@ module ActionMailer
 
     def process(method_name, *args) #:nodoc:
       payload = {
-        :mailer => self.class.name,
-        :action => method_name
+        mailer: self.class.name,
+        action: method_name
       }
 
       ActiveSupport::Notifications.instrument("process.action_mailer", payload) do
diff --git a/actionmailer/test/fixtures/base_mailer/email_with_translations.html.erb b/actionmailer/test/fixtures/base_mailer/email_with_translations.html.erb
index 30466dd005..d676a6d2da 100644
--- a/actionmailer/test/fixtures/base_mailer/email_with_translations.html.erb
+++ b/actionmailer/test/fixtures/base_mailer/email_with_translations.html.erb
@@ -1 +1 @@
-<%= t('.greet_user', :name => 'lifo') %>
\ No newline at end of file
+<%= t('.greet_user', name: 'lifo') %>
\ No newline at end of file
diff --git a/actionmailer/test/fixtures/test_mailer/included_subtemplate.text.erb b/actionmailer/test/fixtures/test_mailer/included_subtemplate.text.erb
index a93c30ea1a..ae3cfa77e7 100644
--- a/actionmailer/test/fixtures/test_mailer/included_subtemplate.text.erb
+++ b/actionmailer/test/fixtures/test_mailer/included_subtemplate.text.erb
@@ -1 +1 @@
-Hey Ho, <%= render :partial => "subtemplate" %>
\ No newline at end of file
+Hey Ho, <%= render partial: "subtemplate" %>
\ No newline at end of file
diff --git a/actionmailer/test/mailers/base_mailer.rb b/actionmailer/test/mailers/base_mailer.rb
index 6584bf5195..bd991e209e 100644
--- a/actionmailer/test/mailers/base_mailer.rb
+++ b/actionmailer/test/mailers/base_mailer.rb
@@ -120,7 +120,7 @@ class BaseMailer < ActionMailer::Base
   end
 
   def with_nil_as_return_value
-    mail(:template_name => "welcome")
+    mail(template_name: "welcome")
     nil
   end