diff --git a/Gemfile b/Gemfile
index 43766f40..59b0bef1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -67,7 +67,7 @@ group :test do
 end
 
 group :production, :staging, :deploy  do
-  gem 'puma', '~> 4.3.5'
+  gem 'puma', '~> 4.3.9'
 end
 
 group :doc do
diff --git a/Gemfile.lock b/Gemfile.lock
index 6d7ffafa..e246f284 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -294,7 +294,7 @@ GEM
       net-ssh (>= 2.6.5, < 6.0.0)
     net-ssh (5.2.0)
     netrc (0.11.0)
-    nio4r (2.5.2)
+    nio4r (2.5.8)
     nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     oauth (0.5.4)
@@ -333,7 +333,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.1.1)
-    puma (4.3.5)
+    puma (4.3.9)
       nio4r (~> 2.0)
     rabl (0.14.1)
       activesupport (>= 2.3.14)
@@ -551,7 +551,7 @@ DEPENDENCIES
   omniauth-facebook
   omniauth-google-oauth2
   pry
-  puma (~> 4.3.5)
+  puma (~> 4.3.9)
   rabl
   rails (~> 4.2)
   rails-erd!