ambiguous reference

gistfile1.txt

// Ojc Category on NSError
@interface NSError (MyCategory)
+ (NSError *) clientErrorWithCode: (NSInteger) code;
@end

// Swift Error Enum
@objc enum AppError : Int {
  case Foo = 0
  case Bar = 1
}

// Swift Extension on NSError
extension NSError {
    func clientErrorWithCode(code:AppError) {
        NSError.clientErrorWithCode(code.rawValue)
    }
}

// Try to use:
let error = NSError.clientErrorWithCode(.Foo)  // Error: Error:(268, 40) ambiguous reference to member 'clientErrorWithCode'