diff --git a/Gemfile.lock b/Gemfile.lock
index e5a7757..45f9e58 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -18,7 +18,7 @@ GEM
       tilt
     multi_json (1.12.1)
     nio4r (2.5.2)
-    puma (4.3.1)
+    puma (4.3.9)
       nio4r (~> 2.0)
     rack (1.6.12)
     rack-protection (1.5.5)