Why does a wrong override compile ? (MinGW)

Why does a wrong override compile ? (MinGW)

I have this code :
class A
{
virtual void operator()(std::complex<double>* const input_spectrum,
double* const noise_spectrum) = 0;
};
class B : public A
{
virtual void operator()(std::complex<double>* input_spectrum,
double* noise_spectrum) override;
}
I don't get why it compiles ? The const qualifiers are different, so it
should throw an error, doesn't it ?. Running under MinGW 4.8