[conv.ptr] p2 says

A prvalue of type “pointer to cv T”, where T is an object type, can be converted to a prvalue of type “pointer to cv void”.

The notation cv denotes the cv-qualification of the pointed-to type, which is used as the cv-qualification of the pointed-to type of the destination type. Consider this example:

int* ptr = 0;
void const* vptr = ptr;  // #1

#1 is ok but the source type is "pointer to int" while the destination type is "pointer to const void". In this case, the cv-qualification of the pointed-to types are different.

The change might be

A prvalue of type “pointer to cv1 T” can be converted to a prvalue of type “pointer to cv2 void”, where T is an object type and cv2 is the same cv-qualification as, or greater cv-qualification than, cv1.