diff --git a/Gemfile b/Gemfile
index 8079ec3..98e45be 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,6 +15,9 @@ gem "actionpack-action_caching"
 gem "actionpack-xml_parser"
 gem "loofah", "~> 2.0"
 
+# Request at least nokogiri 1.6.7.1 because of security advisories
+gem "nokogiri", ">= 1.6.7.1"
+
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :x64_mingw, :mswin, :jruby]
 gem "rbpdf", "~> 1.18.7"