Zip the contents of a folder without including the folder itself

I have a directory called folder that looks like this: folder -> root_folder -> some files I want to zip this directory into zipped_dir, I tried: zip -r zipped_dir.zip folder/* But this generates a ZIP that looks like this: zipped_dir -> folder -> root_folder -> some files in other words, it's including the directory whose contents I want to zip. How can I exclude this parent directory from the ZIP, without moving anything? IE I would like this end result: zipped_dir -> root_folder -> some files