QQuaternion - Warning Implicit conversion from 'float' to 'double'

Warning from compiler about implicit conversion in QQuaternion::inverted()

/usr/local/Trolltech/Qt5.7/5.7/gcc_64/include/QtGui/qquaternion.h:204: avertissement : implicit conversion from 'float' to 'double' to match other operand of binary expression [-Wdouble-promotion]
return QQuaternion(wp / len, -xp / len, -yp / len, -zp / len);
^