We present a new experimental approach using high-resolution scanning transmission electron microscopy (HRSTEM) to unambiguously identify the nature of intrinsic stacking faults in the $L1_2$ $\gamma^\prime$ phase of the $\gamma/\gamma^\prime$ microstructure of superalloys. Since complex (CISF) and superlattice stacking faults (SISF) may look identical in a given <110> projection, our approach includes viewing the fault in a nearby <112> direction, enabling its reliable and unambiguous identification. We have applied this method to confirm the defect structures postulated for SESF formation mechanisms by Kolbe et al. and Vorontsov et al., verifying the presence of a complex leading segment in both cases.