diff --git a/Gemfile b/Gemfile
index 9304b25c..5542f314 100644
--- a/Gemfile
+++ b/Gemfile
@@ -40,7 +40,7 @@ gem 'oauth2', '1.0.0'
 gem 'paper_trail'
 gem 'paperclip-azure', '~> 0.2'
 gem 'preamble', '0.0.3'
-gem 'puma'
+gem 'puma', '5.6.8'
 gem 'rack', '1.6.13'
 gem 'rails', '4.2.11.1'
 gem 'remotipart', '~> 1.2'
diff --git a/Gemfile.lock b/Gemfile.lock
index a6e9e145..dac02b48 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -355,7 +355,7 @@ GEM
       net-protocol
     netrc (0.11.0)
     newrelic_rpm (4.0.0.332)
-    nio4r (2.5.8)
+    nio4r (2.7.0)
     no_proxy_fix (0.1.2)
     nokogiri (1.15.3)
       mini_portile2 (~> 2.8.2)
@@ -399,7 +399,7 @@ GEM
     pry-rails (0.3.2)
       pry (>= 0.9.10)
     public_suffix (3.1.1)
-    puma (6.0.0)
+    puma (5.6.8)
       nio4r (~> 2.0)
     racc (1.7.1)
     rack (1.6.13)
@@ -624,7 +624,7 @@ DEPENDENCIES
   paperclip-azure (~> 0.2)
   preamble (= 0.0.3)
   pry-rails
-  puma
+  puma (= 5.6.8)
   rack (= 1.6.13)
   rails (= 4.2.11.1)
   rails-assets-font-awesome (~> 4.2.0)!