diff --git a/Gemfile b/Gemfile
index cdf798137..4baa9a502 100644
--- a/Gemfile
+++ b/Gemfile
@@ -26,7 +26,7 @@ gem 'geocoder'
 gem 'lodash-rails'
 gem 'typhoeus'
 gem 'sassc-rails'
-gem 'puma'
+gem 'puma', '>= 4.3.9'
 gem 'rack-attack'
 
 group :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index 44e3cebc3..ccc7cf216 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -227,7 +227,8 @@ GEM
       websocket-driver (>= 0.2.0)
     powerpack (0.1.1)
     public_suffix (2.0.5)
-    puma (3.7.1)
+    puma (5.5.2)
+      nio4r (~> 2.0)
     rabl (0.13.1)
       activesupport (>= 2.3.14)
     rack (2.0.1)
@@ -430,7 +431,7 @@ DEPENDENCIES
   omniauth-twitter
   pg
   poltergeist
-  puma
+  puma (>= 4.3.9)
   rabl
   rack-attack
   rack-canonical-host
@@ -461,4 +462,4 @@ RUBY VERSION
    ruby 2.4.0p0
 
 BUNDLED WITH
-   1.14.6
+   1.17.3