pdfcrop command: Trying to remove white margins using pdfcrop but it removes all links and bookmarks

I have a pdf document and i am trying to remove the white margins.

So i am using the following command

pdfcrop --margin 5 input.pdf output.pdf

Now when i look into my pdf it has all the bookmarks(or contents) removed and also i have links to various pages, the links no more work.

HOw to keep intact the contents and the links while modifying a pdf