The provision of basic services is falling short in informal settlements of cities in the Global South. In particular, public utilities have had difficulties expanding their services to the urban poor. Why is this the case despite utilities having improved their capabilities substantially over the last years? This paper investigates how innovation strategies of utilities are aligned or misaligned with the broader contexts in informal settlements, which are populated by different socio-technical regimes. We propose a framework to identify new capabilities needed by utilities to deal with these different regimes. The paper reconstructs pro-poor initiatives of a water and sewerage utility in a large East-African city and explains why they tended to fail in terms of livelihood improvement. We show how the alignment between capability portfolios and specific regime structures have set limits to the success of pro-poor innovation strategies in informal settlement contexts.