A method, apparatus, and computer program product provide for improving prediction accuracy of a geometric partitioning merge mode. In the context of a method, the method accesses a coding unit partitioned into a first partition and a second partition. The method also determines whether an enabling value associated with the coding unit is indicative of additional motion vector refinement and, in accordance with a determination that the enabling value associated with the coding unit is indicative of additional motion vector refinement, determines at least one motion vector difference value for at least one partition of the first partition and the second partition. The method additionally applies a prediction of the coding unit in accordance with the at least one motion vector difference value.