In an embodiment, an apparatus, such as a power-supply controller, includes a generator and an adjuster. The generator is configured to provide a switching signal that causes a power supply to generate a regulated output signal, and the adjuster is configured to impart a condition to the power supply while the power supply is operating in a first mode, the condition being approximately equal to a condition that the power supply would have if the power supply were operating in a second mode. For example, such an apparatus may be able to reduce or eliminate a transient on a regulated output signal (e.g., a regulated output voltage) when a power supply transitions from a first operating mode, such as a pulse-frequency-modulation (PFM) mode, to a second operating mode, such as a pulse-width-modulation (PWM) mode.