diff --git a/Gemfile.lock b/Gemfile.lock
index 5f5b3f9f8..d691d4234 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -209,7 +209,8 @@ GEM
       byebug (~> 11.0)
       pry (~> 0.10)
     public_suffix (3.1.1)
-    puma (3.12.1)
+    puma (4.0.0)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-cache (1.9.0)
       rack (>= 0.4)