diff --git a/Gemfile b/Gemfile
index b99461e..89040a4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.2.3'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 
 gem "aws-sdk-s3", '~>1'
 gem 'sinatra'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7e74a65..77c9b67 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -102,7 +102,8 @@ GEM
     nio4r (2.3.1)
     nokogiri (1.10.2)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.1)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-cors (1.0.3)
     rack-protection (2.0.5)
@@ -181,7 +182,7 @@ DEPENDENCIES
   figaro
   jwt
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.3)
   sinatra