Getting FatalErrorException for laravel Class 'log' not found while calling from a Model

While I'm calling \Log::error('error'); from any model such as "User.php" then it's showing following error.

FatalErrorException in User.php line ....: Class 'log' not found

But when I'm using the same code from the Controller its working fine. Could you please let me know how to solve it ?

Thanks in advance

via Chebli Mohamed