Can't gain the `pipeTo` method on [[scala.concurrent.Future]]

As the doc of akka explains, you should be able to gain the pipeTo method on [[scala.concurrent.Future]] this way:

import akka.pattern.pipe
val future = ...
future pipeTo sender()

Unfortunately, I can't do that, i'm getting an error "can't resolve symbol pipeTo" in my IDE.

As a workaround, I had to use the syntax this way

pipe(future) pipeTo sender()

But it still disturb me to not figure out why (i'm quite newby in scala BTW). Thanks a lot to help understand this puzzle.

scala 2.12.2 akka 2.5.3