Issue #5887 has been updated by matz (Yukihiro Matsumoto). Status changed from Assigned to Closed The document has been fixed already: In the first form, returns an array of the names of all constants accessible from the point of call. This list includes the names of all modules and classes defined in the global scope. If you are going to propose alternative name for Module.constant, submit a feature request. It might be difficult due to the compatibility rule. Matz. ---------------------------------------- Bug #5887: The documentation of Module.constants is incorrect https://bugs.ruby-lang.org/issues/5887#change-28118 Author: shugo (Shugo Maeda) Status: Closed Priority: Normal Assignee: shugo (Shugo Maeda) Category: core Target version: ruby -v: ruby 2.0.0dev (2012-01-12 trunk 34015) [i686-linux] The documentation of Module.constants says "Returns an array of the names of all constants defined in the system. This list includes the names of all modules and classes." However, Module.constants returns the names of the constants accessible at the place where the method is called: class A X = 1 p Module.constants.include?(:X) #=> true end Could someone fix the documentation? I can't write a proper English documentation. OT: I think Module.constants should be renamed in the future, because Module.constants is confusing with Module#constants. Why the hell do I have to write the following tricky code to invoke Module#constants on Module itself? p Module.instance_method(:constants).bind(Module).call -- http://bugs.ruby-lang.org/