std.stdio.File.seek error

[stunaep via Digitalmars-d-learn]

I have a very large file I need to read data from at certain 
positions, but I have run into this error
std.conv.ConvOverflowException@std\conv.d(1328): Conversion 
positive overflow
when seeking to 6346890680. Seeking to smaller values such as 
3580720 work with no problem. The file is well over 8GB, so it 
must be able to read data at positions that high.