Creator code model warns about lower 64 bit signed limit

When entering the following line:

 qint64 x = -9223372036854775808ll;

I get a warning in the editor:

"integer literal is too large to be represented in a signed integer type, interpreting as unsigned"

When using a decremented value the warning disappears:

 qint64 x = -9223372036854775807ll;

However I think the lower limit of a signed long long integer is -9223372036854775808 not -9223372036854775807.