The packet processing time (PPT) of an end host (i.e., workstation) is the time elapsed between the arrival of a packet at the data-link layer and the time the packet is processed at the application layer (RFCs 2679). A recent work presented an active scheme to measure PPT over Internet paths using a packet-pair based probing structure considering its importance as a network parameter in the Internet. However, the existing scheme does not consider the effect of interrupt coalescence (IC) in network interface cards (NICs), which are configured with an IC under high transmission speeds. In this paper, we propose an enhancement to the existing scheme for measuring PPT when there is an IC available in the NIC of the workstation under test. The enhanced scheme first detects IC and then measures PPT using the measured gaps of the probing structure. We evaluated the enhanced scheme through testbed experiments using two different workstations and under different transmission speeds, i.e., 10, 100, and 1000 Mb/s. Our results show that the proposed scheme consistently measures PPT with high efficacy.