The integration of prosumers (consumers who can both consume and produce energy) in a current district heating network (DHN) brings new challenges to the market and DHN operation, since they can change the thermal flow in the DHN and increase competition in the district heating market. In this scope, this work proposes the implementation of a coordination methodology based on a peer-to-peer (P2P) market to enable bilateral energy trades between producers, prosumers and consumers, coupled with the DHN operation. A Nordic DHN containing prosumers is used to test and validate the proposed methodology. The results point out that the coordination methodology is able to provide compromise solutions between the market negotiation and the DHN operation. An important conclusion is that the coordination methodology encourages prosumer integration in DHN, increasing market competition that may pull down the energy costs for consumers while avoiding DHN's operating and management burdens.