diff --git a/Scripting-faq.md b/Scripting-faq.md
index 85eccb4..ca7cf9b 100644
--- a/Scripting-faq.md
+++ b/Scripting-faq.md
@@ -2,14 +2,14 @@
 
 ```
 > class String
-* def +
+* def +(s1)
 * end
 * end
  => nil
 > "a" + "b"
  => "ab"
 ```
-This causes a error in CRuby.
+This causes a error in CRuby's irb, and returns ``nil`` in CRuby.
 This behavior is a limitation by the current implementation.
 
 ## I can't alias for global variables.