diff --git a/Gemfile b/Gemfile
index 62968c57200..1903d66e6ab 100644
--- a/Gemfile
+++ b/Gemfile
@@ -286,7 +286,7 @@ gem "newrelic_rpm", '~> 3.9.4.245'
 
 gem 'octokit', '~> 3.7.0'
 
-gem "mail_room", "~> 0.4.2"
+gem "mail_room", "~> 0.5.1"
 
 gem 'email_reply_parser', '~> 0.5.8'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index a4a0762bdd8..eeaddc95a8e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -384,7 +384,7 @@ 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)
@@ -846,7 +846,7 @@ DEPENDENCIES
   jquery-ui-rails (~> 4.2.1)
   kaminari (~> 0.15.1)
   letter_opener (~> 1.1.2)
-  mail_room (~> 0.4.2)
+  mail_room (~> 0.5.1)
   minitest (~> 5.7.0)
   mousetrap-rails (~> 1.4.6)
   mysql2 (~> 0.3.16)