diff --git a/runtime/doc/if_ruby.txt b/runtime/doc/if_ruby.txt
index ba54c1c..c2373b9 100644
--- a/runtime/doc/if_ruby.txt
+++ b/runtime/doc/if_ruby.txt
@@ -194,12 +194,20 @@
 you don't use the Ruby interface you don't need it, thus you can use Vim
 without this DLL file.
 
+You need to install the right version of Ruby for this to work.  You can find
+the package to download from:
+http://www.garbagecollect.jp/ruby/mswin32/en/download/release.html
+Currently that is ruby-1.9.1-p429-i386-mswin32.zip
+
 To use the Ruby interface the Ruby DLL must be in your search path.  In a
 console window type "path" to see what directories are used.
 
 The name of the DLL must match the Ruby version Vim was compiled with.
-Currently the name is "ruby18.dll".  That is for Ruby 1.8.  To know for sure
-edit "gvim.exe" and search for "ruby\d*.dll\c".
+Currently the name is "msvcrt-ruby191.dll".  That is for Ruby 1.9.1.  To know
+for sure edit "gvim.exe" and search for "ruby\d*.dll\c".
+
+If you want to build Vim with Ruby 1.9.1, you need to edit the config.h file
+and comment-out the check for _MSC_VER.
 
 ==============================================================================
  vim:tw=78:ts=8:ft=help:norl: