diff --git a/Gemfile.lock b/Gemfile.lock
index afa9311..66de95f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -185,7 +185,8 @@ GEM
     pry-rails (0.3.6)
       pry (>= 0.10.4)
     public_suffix (2.0.4)
-    puma (3.11.4)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.4)
     rack-mini-profiler (0.10.1)
       rack (>= 1.2.0)