diff --git a/Gemfile.lock b/Gemfile.lock
index fdb369f..8cca807 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -36,7 +36,9 @@ GEM
       multi_json
     multi_json (1.11.2)
     multipart-post (2.0.0)
-    puma (3.0.2)
+    nio4r (2.5.2)
+    puma (4.3.1)
+      nio4r (~> 2.0)
     rack (1.6.4)
     rb-readline (0.5.3)
     redis (3.2.2)