diff --git a/Gemfile.lock b/Gemfile.lock
index 0c7527f4..9bb8aca4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -179,7 +179,7 @@ GEM
     marcel (1.0.4)
     mini_mime (1.1.5)
     minitest (5.25.5)
-    mysql2 (0.5.5)
+    mysql2 (0.5.6)
     net-imap (0.5.8)
       date
       net-protocol