diff --git a/Gemfile b/Gemfile
index 4c74ba02c..0d8784853 100644
--- a/Gemfile
+++ b/Gemfile
@@ -33,7 +33,7 @@ gem 'mini_racer', group: :therubyracer
 
 # Use --without <group> argument to skip unnecessary drivers
 gem 'sqlite3', group: :sqlite
-gem 'mysql2', '~> 0.5.5', group: :mysql
+gem 'mysql2', '~> 0.5.6', group: :mysql
 gem 'pg', '~> 1.5.4', group: :postgresql
 
 group :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index 0d3525dcd..f8c414ebd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -182,7 +182,7 @@ GEM
     minitest-stub-const (0.6)
     mocha (2.1.0)
       ruby2_keywords (>= 0.0.5)
-    mysql2 (0.5.5)
+    mysql2 (0.5.6)
     net-imap (0.4.12)
       date
       net-protocol
@@ -376,7 +376,7 @@ DEPENDENCIES
   mini_racer
   minitest-stub-const
   mocha
-  mysql2 (~> 0.5.5)
+  mysql2 (~> 0.5.6)
   pg (~> 1.5.4)
   puma (~> 6.4)
   rack-mini-profiler