Event Notification Services (ENS) are used in various applications such as remote monitoring and control, stock tickers, traffic control, or facility management. The performance issues of the filtering of primitive events has been widely studied. However, for a growing number of applications, the rapid notification about the occurrence of composite events is an important issue. Currently, the detection of composite events requires a second filtering step after the identification of the primitive components. In this paper, we propose a single-step method for the filtering of composite events. The method has been implemented and tested within our ENS prototype CompAS. Using our method, the filter response time for composite events is significantly reduced. Additionally, the overall performance of the event filtering has been improved.