A pipe coupling for connection to a pipe end of pipe made of polymer material includes an inner sleeve which is intended for insertion into the pipe end and for abutment with the inner surface of the pipe end, and an outer sleeve which is intended for abutment with the outer surface of the pipe end and which includes a slot-like opening. The pipe coupling also includes a device for adjusting the opening, and a pre-widening device positioned between the edges of the slot-like opening. The pre-widening device makes the slot-like opening larger such that the inner diameter of the outer sleeve is larger than the outer diameter of the pipe.