Adding !important using a Compass Mixin

UPDATE: new versions of sass support this syntax now:

@include border-radius(5px !important);

Just do this (as noted in @naoufal answer).

--- old answer ---

You can not use !important with compass mixings, but the culprit is not compass, you should blame sass for this.

@include border-radius(5px) !important; #=> SASS Syntax Error

You can include it inside the mixin like so:

@include border-radius(5px !important);

Compass will output the following:

-webkit-border-radius: 5px !important;
-moz-border-radius: 5px !important;
-ms-border-radius: 5px !important;
-o-border-radius: 5px !important;
border-radius: 5px !important;