Glyphicons of Bootstrap 3.3.5 not displayed in an ember-cli project

I've updated bootstrap-sass to version 3.3.5 in an ember-cli project and since the glyphicons are not displayed anymore. Instead I've got the "square" characters.

I've installed bootstrap-sass with bower. In my brocfile.js, I have included bootstrap-sass in this way:

app.import('bower_components/bootstrap-sass-official/assets/javascripts/bootstrap.js');
app.import('bower_components/bootstrap-sass-official/assets/fonts/bootstrap/glyphicons-halflings-regular.woff2', {destDir: '/fonts/bootstrap'});

I don't have this problem with bootstrap-sass 3.3.4.