Imposters ignoring object rotation

I have the following problem with imposters:

I use the imposterUV node in the material editor, as seen in the picture.
The problem is that the resulting imposter ignores the object’s current rotation. let’s say the object is rotated by 90 degrees on the x axis ingame (because it’s placed on a sphere for example) the resulting imposter has always a rotation of (0,0,0). (example in the pictures)
how can i rotate the imposter so it adapts to the object’s original rotation?