diff --git a/Gemfile b/Gemfile
index c3a159d8..09fff90e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 source "http://rubygems.org"
 gemspec
 
-gem "nokogiri", "~> 1.8.1", force_ruby_platform: true
+gem "nokogiri", "= 1.16.2", force_ruby_platform: true
 gem "posix-spawn", :platforms => :ruby
 gem "redcarpet", :platforms => :ruby
 gem "kramdown", :platforms => :jruby
@@ -12,8 +12,8 @@ gem 'org-ruby', '~> 0.9.12'
 gem 'creole', '~> 0.5.0'
 gem 'idn-ruby', '~> 0.1.5'
 gem 'twitter-text', '~> 3.1'
-gem "wikicloth", "=0.8.3"
+gem "wikicloth", "= 0.8.3"
 gem 'asciidoctor', '~> 2.0', '>= 2.0.21'
 gem 'rake', '~> 13.1'
-gem 'paru'
+gem 'paru', '~> 1.2.0'