Translation support for ion-md-input

[slaff]

I am trying to add localization to my test Ionic + Material Design App ( based on the demo App). I added angular-translate and I am able to use translation for normal HTML elements but I cannot use translation for elements coming from Ionic MD.

For example that one:

<ion-md-input placeholder="{{'Username' | translate}}" highlight-color="balanced" type="text"></ion-md-input>

does not seem to translate the Username.

Any ideas what I am doing wrong?