diff --git a/Gemfile.lock b/Gemfile.lock
index 00504c3..865650c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -124,7 +124,8 @@ GEM
       pry (~> 0.10)
     pry-rails (0.3.9)
       pry (>= 0.10.4)
-    puma (3.12.0)
+    puma (4.3.3)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)