Arduino due and dtostrf function

Hi all,
I have a problem with the function ‘dtostrf’

the sketch is very easy :

void setup()
char temp[8];
dtostrf(0.012, 8 ,2 ,temp);

the arduino IDE is the 1.5.1r2 and I use an Arduino due.
With older IDE version and other Arduino (nano, Uno), I use this function with no problem.

The error message in the IDE is : error: ‘dtostrf’ was not declared in this scope
but I have include stdlib.h

Where is the problem ?
Have you another way to convert a float to string with a specific digit (not for serial.print) ?

thanks in advance for your answer.

This should be in the DUE part of the forum, down near the bottom.