diff --git a/railties/guides/source/ruby_on_rails_guides_guidelines.textile b/railties/guides/source/ruby_on_rails_guides_guidelines.textile
index 26a5a4c3c9..9ae360a73b 100644
--- a/railties/guides/source/ruby_on_rails_guides_guidelines.textile
+++ b/railties/guides/source/ruby_on_rails_guides_guidelines.textile
@@ -62,10 +62,10 @@ To force process of all the guides, pass +ALL=1+.
 
 It is also recommended that you work with +WARNINGS=1+. This detects duplicate IDs and warns about broken internal links.
 
-If you want to generate guides in languages other than English, you can keep them in a separate directory under +source+ (eg. <tt>source/es</tt>) and use the +LANGUAGE+ environment variable:
+If you want to generate guides in languages other than English, you can keep them in a separate directory under +source+ (eg. <tt>source/es</tt>) and use the +GUIDES_LANGUAGE+ environment variable:
 
 <plain>
-rake generate_guides LANGUAGE=es
+rake generate_guides GUIDES_LANGUAGE=es
 </plain>
 
 h3. HTML Validation