diff --git a/Gemfile.lock b/Gemfile.lock
index ec34112a3..64636a4bf 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -425,7 +425,8 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.2)
-    puma (3.12.4)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rabl (0.13.1)
       activesupport (>= 2.3.14)
     rack (2.2.2)