Ember checkbox input helper cannot user 'on' property

Hello Stack Overflowers!

Given:

  <td>{{ input type="checkbox" action="acceptChanges" on="click" class="toggle" checked=user.is_disabled }}</td>

Then when rendering the view an error is thrown:

Uncaught TypeError: string is not a function

However, removing the 'on' property, such that the mark-up is:

<td>{{ input type="checkbox" action="acceptChanges" class="toggle" checked=user.is_disabled }}</td>

Then the page renders. My goal is to bind the "acceptChanges" controller method to changing this value. "acceptChanges" is an ObjectController method that simply saves the object in the store.