Active Links with ampersand character change when uploaded/converted

I have a PDF document that has active links in it. When I upload it to Issuu, it changes the URLs of the embedded links. The change happens only on ampersand characters (&) in the URL. The ampersands are changed to the HTML code for the ampersand (& with amp;) but this unfortunately breaks all my links. I can see that the URL is changed in the Issuu viewer when I hover over the link. So for example:

http://www.domain.com/some&page

is changed to

http://www.domain.com/some& amp;page (without the space)

My URLs need the true ampersand in order to function properly. Is there a way to fix this?