Not swallowing inside script

[NordLZ]

I'm using pandoc to convert markdown files to pdfs and piping the standard input into zathura: pandoc file.md -f markdown -t pdf | zathura - This works when run as a command in the terminal but when I put inside a script:

#! /bin/sh
pandoc $1 -f markdown -t pdf | zathura - 

The terminal does not get swallowed. How can I force bspswallow to swallow the terminal?