diff --git a/Gemfile.lock b/Gemfile.lock
index 9249376..1f7fba7 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -12,7 +12,9 @@ GEM
       rb-inotify (>= 0.9.7)
     mime-types (1.25.1)
     multi_json (1.11.2)
-    puma (2.16.0)
+    nio4r (2.5.7)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (1.6.4)
     rack-protection (1.5.3)
       rack