diff --git a/Gemfile b/Gemfile
index 8d9991f42..86a0c492b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -68,7 +68,7 @@ gem "omniauth-github", "~> 1.3" # OmniAuth strategy for GitHub
 gem "omniauth-twitter", "~> 1.4" # OmniAuth strategy for Twitter
 gem "patron", "~> 0.13.3" # HTTP client library based on libcurl, used with Elasticsearch to support http keep-alive connections
 gem "pg", "~> 1.2" # Pg is the Ruby interface to the PostgreSQL RDBMS
-gem "puma", "~> 5.0" # Puma is a simple, fast, threaded, and highly concurrent HTTP 1.1 server
+gem "puma", "~> 4.3" # Puma is a simple, fast, threaded, and highly concurrent HTTP 1.1 server
 gem "pundit", "~> 2.1" # Object oriented authorization for Rails applications
 gem "pusher", "~> 1.3" # Ruby library for Pusher Channels HTTP API
 gem "pusher-push-notifications", "~> 1.3" # Pusher Push Notifications Ruby server SDK
diff --git a/Gemfile.lock b/Gemfile.lock
index 530c3c742..57171df7f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -476,7 +476,7 @@ GEM
     naught (1.1.0)
     nenv (0.3.0)
     netrc (0.11.0)
-    nio4r (2.5.4)
+    nio4r (2.5.3)
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     notiffany (0.1.3)
@@ -527,7 +527,7 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (4.0.6)
-    puma (5.0.0)
+    puma (4.3.6)
       nio4r (~> 2.0)
     pundit (2.1.0)
       activesupport (>= 3.0.0)
@@ -932,7 +932,7 @@ DEPENDENCIES
   pry (~> 0.13)
   pry-byebug (~> 3.8)
   pry-rails (~> 0.3)
-  puma (~> 5.0)
+  puma (~> 4.3)
   pundit (~> 2.1)
   pundit-matchers (~> 1.6)
   pusher (~> 1.3)
diff --git a/vendor/cache/nio4r-2.5.3.gem b/vendor/cache/nio4r-2.5.3.gem
new file mode 100644
index 000000000..9947d76b0
Binary files /dev/null and b/vendor/cache/nio4r-2.5.3.gem differ
diff --git a/vendor/cache/nio4r-2.5.4.gem b/vendor/cache/nio4r-2.5.4.gem
deleted file mode 100644
index f5eaa0c43..000000000
Binary files a/vendor/cache/nio4r-2.5.4.gem and /dev/null differ
diff --git a/vendor/cache/puma-4.3.6.gem b/vendor/cache/puma-4.3.6.gem
new file mode 100644
index 000000000..c6d90c398
Binary files /dev/null and b/vendor/cache/puma-4.3.6.gem differ
diff --git a/vendor/cache/puma-5.0.0.gem b/vendor/cache/puma-5.0.0.gem
deleted file mode 100644
index d31bc19dc..000000000
Binary files a/vendor/cache/puma-5.0.0.gem and /dev/null differ