diff --git a/Gemfile.lock b/Gemfile.lock
index 3831228..84d233b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -186,7 +186,8 @@ GEM
       rack
     pg (0.21.0)
     popper_js (1.14.5)
-    puma (3.10.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-pjax (1.0.0)
       nokogiri (~> 1.5)