Bash == not found

I have a small bash script:

#!/bin/bash
if [[ "$@" == "pull" ]]
then
    # stuff 
elif [[ "$@"== "push" ]]
then
   # stuff
else
    echo "Command not recognised"
fi

it's located in /usr/bin/local and I made it executable. However whenever I run it I get script:1: == not found

Any ideas?

This is macOS if that matters.