We report on experimental observations of a phenomenon whereby optical coupling of a high-power laser to a photonic subsystem locks a silicon microring’s resonance if temperature of the photonic device is allowed to drift, causing the thermal tuning control to fail. This is the first report of such a failure mechanism, to our knowledge. We refer to this effect as “optical hijacking” of the resonator wavelength. We demonstrate this effect showing that a ring resonator whose resonance drifts due to an increase in chip temperature can be locked to a normally nonresonant wavelength by injecting high optical power to the system leading to this “optical hijacking” effect. Additionally, an analytical description of this effect is presented.