The idea behind event-triggered control theory is to aperiodically schedule control data transmissions between an embedded processor and a physical system based on event rules. While this theory can effectively reduce control data transmissions, the resulting closed-loop system performance can significantly deviate from its ideal (i.e., non-event-triggered) closed-loop system performance. Furthermore, the selection of the parameters of the event rules can be a challenge in obtaining a satisfactory closed-loop system performance that stays close to its ideal one. Motivated by this standpoint, the contribution of this paper is to make the first attempt in rigorously addressing this problem, where we propose a corrective signal for recovering the ideal closed-loop system performance in event-triggered control. The key feature of the proposed corrective signal is that the closed-loop system performance approaches its ideal one in a quantifiable manner as the gain of this corrective signal is increased. System-theoretical analysis of the proposed method is presented and illustrative numerical examples are also given to demonstrate the efficacy of our contribution.