A network device includes control logic coupled to a receiver. The network device receives, via the receiver, a packet from a second network device over a network, wherein the packet is associated with clock synchronization between the network device and the second network device. The network device determines that a congestion indicator of the packet is asserted, indicating that the packet has incurred congestion traversing the network and adjust, based on an assertion of the congestion indicator, a weight applied to timestamps associated with the packet in performing clock synchronization with the second network device.