GaAs/Ge/GaAs heterostructures have been grown by molecular beam epitaxy on GaAs substrates with nominally (100) and (100) tilted 4° towards [01¯1] orientations. High‐energy electron diffraction is used to study the antiphase boundaries of the GaAs grown on epitaxial Ge. We have observed the annihilation of GaAs antiphase boundaries on Ge grown on (100) GaAs substrates. GaAs on Ge grown on tilted substrates is observed to be free of antiphase domains.