diff --git a/Gemfile b/Gemfile
index e115d58..91598a7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@
 source 'https://rubygems.org'
 source 'https://rails-assets.org'
 
-gem "middleman", "~> 3.3.3"
+gem "middleman", "~> 4.3.8"
 
 # In order to get SASS 3.3, compass 1.0 is needed
 # FIXME: Remove this once 1.0 is final (very, very soon now -- next week?)
@@ -91,7 +91,7 @@ gem "coderay"
 gem "stringex"
 
 # Markdown
-gem "kramdown"
+gem "kramdown", ">= 2.3.1"
 
 gem 'open-uri-cached'