diff --git a/Gemfile.lock b/Gemfile.lock
index 2dc5f0d657f..0dbac5031f1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -144,6 +144,7 @@ GEM
     multi_json (1.14.1)
     multipart-post (2.0.0)
     netrc (0.11.0)
+    nio4r (2.5.2)
     nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     nokogumbo (2.0.2)
@@ -164,7 +165,8 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (4.0.4)
-    puma (3.12.4)
+    puma (4.3.3)
+      nio4r (~> 2.0)
     rack (1.6.13)
     rack-jekyll (0.5.0)
       jekyll (>= 1.3)