diff --git a/Gemfile b/Gemfile
index 5286540d5..04cf1d38e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 source 'https://rubygems.org'
-ruby '>= 2.4.0', '< 3.0.0'
+ruby '>= 2.5.0', '< 3.0.0'
 
 gem 'pkg-config', '~> 1.4'
 
diff --git a/README.md b/README.md
index 7db66abfa..9ef4acb17 100644
--- a/README.md
+++ b/README.md
@@ -68,8 +68,8 @@ Mastodon acts as an OAuth2 provider so 3rd party apps can use the REST and Strea
 **Requirements:**
 
 - **PostgreSQL** 9.5+
-- **Redis**
-- **Ruby** 2.4+
+- **Redis** 4+
+- **Ruby** 2.5+
 - **Node.js** 10.13+
 
 The repository includes deployment configurations for **Docker and docker-compose**, but also a few specific platforms like **Heroku**, **Scalingo**, and **Nanobox**. The [**stand-alone** installation guide](https://docs.joinmastodon.org/admin/install/) is available in the documentation.