133 Contribution of MCD to moral craftsmanship reflection about morally challenging situations and sharing staff’s own (ethical) expertise. After all, following teams for a year and a half, with only 35% of the participants from the intervention group (post-measurement) participating in 7 or more MCD sessions, does not provide a full picture of the possible impact that MCD can have on MCS within DCIA. The explorative MCS questionnaire should be shortened, further adapted and validated based on the many insights from this research. Validation of this questionnaire would help to make it more compact and reliable; for example, by examining how to include items that are less open to different interpretations. With a validated questionnaire, it may become possible to map the impact of ESS and other interventions on MCS more efficiently. In this study we merely looked at the impact of MCD on the participants’ MCS and which elements of MCD affected the views and actions of the staff who took part in MCD. However, developing MCS should be part of a broader policy that fosters a moral climate of openness and transparency on several levels in the organization and in various ways (Hartman et al., 2020). In future research, we can look beyond just the staff, and also include organizational aspects and pre-conditions to promote a climate of joint moral reflection. CONCLUSION This unique and innovative research examined the impact of a series of MCD sessions on elements of the MCS of Dutch prison staff. A positive development was observed in some elements of MCS after participation in MCD. However, the number of items that showed positive development was limited. We elaborated on possible reasons for this. The potential of ESS, and MCD in particular, for Dutch prisons has not yet been fully achieved. Regarding follow-up research into the impact of MCD on MCS, we advise shortening and validating the questionnaire to measure impact of future ESS on MCS. The (further) development of MCS of prison staff is not something that is finished at some point. It should be an integrated part of working in prisons. This study shows some first positive elements of MCD impact on MCS, which we believe justifies further investment in and investigation of the potential value of a structured moral reflection on the ongoing moral challenges in Dutch prisons. 5