diff --git a/runtime/doc/if_ruby.txt b/runtime/doc/if_ruby.txt
index f79ecc1..0977397 100644
--- a/runtime/doc/if_ruby.txt
+++ b/runtime/doc/if_ruby.txt
@@ -1,4 +1,4 @@
-*if_ruby.txt*   For Vim version 8.0.  Last change: 2016 Sep 01
+*if_ruby.txt*   For Vim version 8.0.  Last change: 2018 Mar 15
 
 
 		  VIM REFERENCE MANUAL    by Shugo Maeda
@@ -221,6 +221,9 @@
 If you want to build Vim with RubyInstaller 1.9 or 2.X using MSVC, you need
 some tricks.  See the src/INSTALLpc.txt for detail.
 
+If Vim is built with RubyInstaller 2.4 or later, you may also need to add
+"C:\Ruby<version>\bin\ruby_builtin_dlls" to the PATH environment variable.
+
 
 Unix ~