bower automatically update bower.json

I run the following commands using bower 1.0.0:

mkdir testdir;cd testdir
bower init #accept defaults
bower install jquery -s  #the -s is supposed to cause update of bower.json
less bower.json

In bower.json I expect to see dependencies listed, but there are none. What is going on?

NOTE: bower install jquery --save does work

NOTE:
The option I am referring to was documented through bower help install

**-S**, --save              Save installed packages into the project's bower.json dependencies