diff --git a/Gemfile.lock b/Gemfile.lock
index 9930597..fd20b54 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -212,7 +212,7 @@ GEM
     minitest (5.22.2)
     multi_json (1.15.0)
     multi_xml (0.6.0)
-    mysql2 (0.5.5)
+    mysql2 (0.5.6)
     net-http (0.4.1)
       uri
     net-imap (0.4.10)