Designing knowledge management systems (KMS) from sociomaterial (SM) tenets has the potential to improve coordination in knowledge sharing activities. However, current information systems knowledge lacks enough guidance on how to go about sociomaterial design. In this Design Science Research (DSR) study we present a set of sociomaterial design guidelines for KMS that enable knowledge sharing (KS) in the historical and cultural heritage domain. We carried out three DSR iterations to define design requirements, formulate sociomaterial design guidelines, and instantiate and evaluate these through a prototypical instantiation of a KMS. This research contributes to the IS literature by presenting an actionable set of guidelines for applying SM principles in designing new KMS. The capability of this design approach has been demonstrated through a KMS validation in an international and interorganizational KS network. We demonstrate how technology designers can use sociomateriality as a design lens enabling them to further create IT-based coordination mechanisms and we show the value of considering SM design to advance in overcoming coordination issues for sharing knowledge.