diff --git a/Gemfile.lock b/Gemfile.lock
index 5ce0a5f..7984d36 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -134,7 +134,8 @@ GEM
       pry (~> 0.10)
     pry-rails (0.3.8)
       pry (>= 0.10.4)
-    puma (3.12.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-proxy (0.6.5)
       rack