Terminal installer: Error trying to locate volume at /Applications

I'm trying to install a pkg from the terminal. It works as

sudo installer -pkg desktop/test/firefox.pkg -target /

but this sends it to the root folder and I need it to go to the Applications folder. And when I have it as

sudo installer -pkg desktop/test/firefox.pkg -target /Applications

I get the error: installer: Error trying to locate volume at /Applications