diff --git a/Gemfile.lock b/Gemfile.lock
index a5378b21..0ad11d66 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -73,11 +73,13 @@ GEM
     minitest (5.11.3)
     mysql2 (0.3.21)
     newrelic_rpm (3.9.9.275)
+    nio4r (2.5.8)
     nokogiri (1.6.8.1)
       mini_portile2 (~> 2.1.0)
     pg (0.18.4)
     psych (2.0.17)
-    puma (3.11.3)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     racc (1.4.14)
     rack (1.6.9)
     rack-test (0.6.3)