As sanitation and hygiene programmes mature, the challenge shifts from bringing communities to ODF status to sustaining this status. In this context, many programmes are confronted with the issue of slippage. This concept refers to a return to previous unhygienic behaviours, or the inability of some or all community members to continue to meet all ODF criteria. This paper explores how to discern slippage nuances and patterns, strategies to address, pre-empt and mitigate it as well as alternative monitoring systems that capture the complexity of slippage more fully. The analysis and reflections are based on direct field experience, primarily from the GSF-supported programme in Madagascar. Moreover, the underpinning principle of the paper is that slippage is an expected aspect of behaviour change-oriented sanitation and hygiene interventions, especially those at scale, and not a sign of failure thereof.