diff --git a/Gemfile.lock b/Gemfile.lock
index 55ea3bc..6dfa842 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -95,7 +95,7 @@ GEM
     method_source (1.0.0)
     mini_mime (1.1.2)
     minitest (5.15.0)
-    mysql2 (0.5.3)
+    mysql2 (0.5.5)
     net-imap (0.2.3)
       digest
       net-protocol