diff --git a/Gemfile.lock b/Gemfile.lock
index ee47517..c8c5ea4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -150,7 +150,8 @@ GEM
     pry-rails (0.3.6)
       pry (>= 0.10.4)
     public_suffix (2.0.5)
-    puma (3.8.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.1)
     rack-canonical-host (0.2.2)
       addressable (> 0, < 3)