diff --git a/Gemfile b/Gemfile
index bb94df8..d9556fb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,7 @@
 # frozen_string_literal: true
 
 source "https://rubygems.org"
+
+gem "jekyll", "~> 4.0"
+
 gemspec
diff --git a/Gemfile.lock b/Gemfile.lock
index 83306f3..29bb190 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -76,6 +76,7 @@ PLATFORMS
 DEPENDENCIES
   bundler (~> 2.0)
   html5up-readonly!
+  jekyll (~> 4.0)
   rake (~> 12.0)
 
 BUNDLED WITH
diff --git a/README.md b/README.md
index d5f500e..4dbbe22 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ TODO: Delete this and the text above, and describe your gem
 Add this line to your Jekyll site's `Gemfile`:
 
 ```ruby
-gem "html5up-readonly"
+gem "html5up-readonly", "~> 0.1", github: 'digitaladapt/html5up-readonly'
 ```
 
 And add this line to your Jekyll site's `_config.yml`: