diff --git a/Gemfile.lock b/Gemfile.lock
index 0d8a8ca..4a8202f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -144,7 +144,7 @@ GEM
     method_source (1.1.0)
     mini_mime (1.1.5)
     minitest (5.25.1)
-    mocha (2.5.0)
+    mocha (2.7.1)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.7.5)
     net-imap (0.5.1)