This disclosure relates to techniques for indicating that a video frame is coded as a generalized P/B (GPB) frame in order to reduce a cost of coding and constructing a second reference picture list in video coding. For a GPB frame, which has identical reference picture lists, signaling and constructing both the first and second reference picture lists may be redundant. The techniques of this disclosure may include coding syntax elements indicating that the video frame is coded as the GPB frame, and coding syntax elements indicating a number of reference pictures and reference picture list construction commands for only a first reference picture list. The techniques also include constructing the first reference picture list based on the syntax elements, and then creating the second reference picture list as a duplicate of the first reference picture list.