We suggest a method for suppression of collective synchrony in an ensemble of all-to-all interacting units. The suppression is achieved by organizing an interaction between the ensemble and a passive oscillator. Technically, this can be easily implemented by a simple feedback scheme. The important feature of our approach is that the feedback signal vanishes as soon as the control is successful. The technique is illustrated by the simulation of a model of an isolated population of neurons. We discuss the possible application of the technique in neuroscience.