Pagination suffix & reuse_query_string problem

Hi everyone.

I'm having trouble with CI pagination class.
My URL looks like: http://domain.com/chapter/2?var=value#anchor, where 2 is a number of a page added by pagination class.
I want my pagination to use #anchor suffix each time when user selects another page and also I need to keep query string ?var=value.

As I can see in the manual I need to use:

Code:

$config['reuse_query_string'] = TRUE;
$config['suffix'] = '#anchor';

But when I'm trying to set config in such a way, my pagination links redirecting users to: http://domain.com/chapter/2#anchor?var=value instead of http://domain.com/chapter/2?var=value#anchor.

I can't understand why it's happening 
Could anyone, please, give me an advice?

Thanks in advance!