diff --git a/Gemfile b/Gemfile
index 78a22e4e954..d98af77e076 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 ruby '2.6.3'
 
 gem 'faraday'
-gem 'html-proofer', '~> 3.0'
+gem 'html-proofer', '~> 3.19', '>= 3.19.3'
 gem 'jekyll', '>=3.1.6'
 gem 'jekyll-paginate'
 gem 'jekyll-redirect-from'
@@ -19,7 +19,7 @@ gem 'rubocop', group: :test
 
 # All of this is for Slate / middleman
 
-gem "middleman", '~> 3.0'
+gem "middleman", "~> 4.1", ">= 4.1.8"
 
 # For syntax highlighting
 gem "middleman-syntax"