The Mohring–Harwitz (1962) theorem states that the degree of self-financing of congested infrastructure is equal to the elasticity of the capacity cost function in the optimum, so that under neutral scale economies exact self-financing applies. The theorem breaks down when the infrastructure is used by operators with market power, the case in point often being airlines at a congested airport. This paper proposes a regulatory scheme that restores self-financing in such cases; partially so in general, and perfectly so under specific circumstances that include (1) the satisfaction of a particular proportionality condition, and (2) either the isolation of budgets needed for subsidies to counter demand-related mark-ups, or perfectly elastic demands so that such mark-ups are zero. Moreover, exact self-financing applies in this scheme independent of the elasticity of the capacity cost function, and occurs for both parametric and “manipulable” congestion pricing.