diff --git a/README.md b/README.md
index 93941b3f9562f9f953f638cb3d15df811dd6d644..492099aab339b556fc30ee21890ee852f9c9342c 100644
--- a/README.md
+++ b/README.md
@@ -50,7 +50,10 @@ pandoc:
       latex:
       pdf: '--latex-engine=xelatex'
       epub: '--epub-chapter-level=2'
-
+    lang:
+      ar:
+        all: '-V mainfont="Amiri"'
+        pdf: '--include-in-header=_layouts/rtl.tex'
 ```
 
 * `markdown: pandoc` will instruct jekyll to use the pandoc html
@@ -93,6 +96,11 @@ regular jekyll site build.
 * `full_file` generates a single file containing all articles, sectioned
   by their main category (the first one defined if many).
 
+* `lang` is a hash where you can define per-language flags.  If you have
+  a `lang` attribute in your site config, this plugin will add the
+  `-V lang=XX` flag and any language-specific flag you want.  You can
+  define language flags for `all` formats or for specific formats.
+
 **IMPORTANT**: As of version 0.1.0 the syntax of the config changed.
 Please upgrade your `_config.yml` accordingly.
 
diff --git a/lib/jekyll-pandoc-multiple-formats/converter.rb b/lib/jekyll-pandoc-multiple-formats/converter.rb
index 7123226227b8ffee4b4089642e3b03e32c391ada..76e0badac7663c5c6d4770a6890f8315d2c45312 100644
--- a/lib/jekyll-pandoc-multiple-formats/converter.rb
+++ b/lib/jekyll-pandoc-multiple-formats/converter.rb
@@ -45,11 +45,16 @@ module JekyllPandocMultipleFormats
       base.class_eval do
         # Just return html5
         def convert(content)
-          flags  = "#{@config['pandoc']['flags']} #{@config['pandoc']['site_flags']}"
+          lang  = @config.dig('lang')
+          flags = []
+          flags << @config.dig('pandoc', 'flags')
+          flags << @config.dig('pandoc', 'site_flags')
+          flags << @config.dig('pandoc', 'lang', lang, 'all')
 
           output = ''
           Dir::chdir(@config['source']) do
-            Open3::popen3("pandoc -t html5 #{flags}") do |stdin, stdout, stderr, thread|
+            cmd = "pandoc -t html5 #{flags.compact.join(' ')}"
+            Open3::popen3(cmd) do |stdin, stdout, stderr, thread|
               stdin.puts content
               stdin.close
 
diff --git a/lib/jekyll-pandoc-multiple-formats/pandoc_file.rb b/lib/jekyll-pandoc-multiple-formats/pandoc_file.rb
index a670807656d713fb5f82ccd24a6ad55265a9e759..aefcbd6f42af60b7ee8ec93dd025aa04b4af1aab 100644
--- a/lib/jekyll-pandoc-multiple-formats/pandoc_file.rb
+++ b/lib/jekyll-pandoc-multiple-formats/pandoc_file.rb
@@ -1,4 +1,4 @@
-# Copyright (c) 2012-2015 Nicolás Reynolds <fauno@endefensadelsl.org>
+# Copyright (c) 2012-2018 Nicolás Reynolds <fauno@endefensadelsl.org>
 #               2012-2013 Mauricio Pasquier Juan <mpj@endefensadelsl.org>
 #               2013      Brian Candler <b.candler@pobox.com>
 # 
@@ -253,13 +253,27 @@ module Jekyll
         @flags << @config['full_flags']
       end
 
-      @flags.join ' '
+      if site_lang?
+        @flags << "-V lang=#{site_lang}"
+        @flags << @config.dig('lang', site_lang, 'all')
+        @flags << @config.dig('lang', site_lang, @format)
+      end
+
+      @flags.compact.join ' '
     end
 
     def command
       'pandoc ' << flags
     end
 
+    def site_lang
+      @site.config.dig('lang')
+    end
+
+    def site_lang?
+      !site_lang.nil?
+    end
+
     def full?
       @extra[:full]
     end