diff --git a/Aer-v1.0-Specification.md b/Aer-v1.0-Specification.md
index fe0f881..b8889e1 100644
--- a/Aer-v1.0-Specification.md
+++ b/Aer-v1.0-Specification.md
@@ -512,7 +512,7 @@ Anonymous functions, also known as closures, allow the creation of functions whi
     $anon(); // You should see 'Hello World!'
     $anon('Welcome guest!'); //You should see 'Welcome guest!'
 
-Anonymous function can be defined in a method body.
+Anonymous function can be defined in a method body. Unlike methods, a closures are limited to return only a primitive data types listed in chapter 4.6.
 
 ## 9. Static Variables & Constant
 Aer lets use any complex expressions including method calls as an initialization values for your static variables and constants.