diff --git a/Gemfile.lock b/Gemfile.lock
index d2b675c..20561f8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -157,7 +157,7 @@ GEM
     marcel (1.0.2)
     mini_mime (1.1.5)
     mini_portile2 (2.8.5)
-    minitest (5.20.0)
+    minitest (5.21.1)
     mocha (2.1.0)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.7.2)