How to upgrade ember.js version

I upgraded ember-cli to version 2.4.3

npm install -g ember-cli

I can see -- ember-cli@2.4.3 , in the listed dependencies, but when I check :

(master *)$ ember -v
version: 2.4.2
node: 5.6.0
os: darwin x64

ember version is still 2.4.2

what's wrong ?