diff --git a/Gemfile b/Gemfile
index 6d371f27a34..f6b2a0a41da 100644
--- a/Gemfile
+++ b/Gemfile
@@ -273,6 +273,6 @@ gem "newrelic_rpm"
 
 gem 'octokit', '3.7.0'
 
-gem "mail_room", "~> 0.4.2"
+gem "mail_room", "~> 0.5.1"
 
 gem 'email_reply_parser'
diff --git a/Gemfile.lock b/Gemfile.lock
index ab743c7d590..6a82d99a14f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -370,7 +370,7 @@ GEM
       systemu (~> 2.6.2)
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
-    mail_room (0.4.2)
+    mail_room (0.5.1)
     method_source (0.8.2)
     mime-types (1.25.1)
     mimemagic (0.3.0)
@@ -813,7 +813,7 @@ DEPENDENCIES
   jquery-ui-rails
   kaminari (~> 0.15.1)
   letter_opener
-  mail_room (~> 0.4.2)
+  mail_room (~> 0.5.1)
   minitest (~> 5.3.0)
   mousetrap-rails
   mysql2
@@ -889,3 +889,6 @@ DEPENDENCIES
   virtus
   webmock (~> 1.21.0)
   wikicloth (= 0.8.1)
+
+BUNDLED WITH
+   1.10.5