diff --git a/runtime/doc/if_ruby.txt b/runtime/doc/if_ruby.txt
index 8968644..e4dfa3f 100644
--- a/runtime/doc/if_ruby.txt
+++ b/runtime/doc/if_ruby.txt
@@ -58,6 +58,9 @@
 	EOF
 	endfunction
 <
+To see what version of Ruby you have: >
+	:ruby print RUBY_VERSION
+<
 
 						*:rubydo* *:rubyd* *E265*
 :[range]rubyd[o] {cmd}	Evaluate Ruby command {cmd} for each line in the