diff --git a/tests/other_codes/vs_GprMax_oldCcode/antenna_GSSI_1500_fs/antenna_GSSI_1500_fs.out b/tests/other_codes/vs_GprMax_oldCcode/antenna_GSSI_1500_fs/antenna_GSSI_1500_fs.h5
similarity index 100%
rename from tests/other_codes/vs_GprMax_oldCcode/antenna_GSSI_1500_fs/antenna_GSSI_1500_fs.out
rename to tests/other_codes/vs_GprMax_oldCcode/antenna_GSSI_1500_fs/antenna_GSSI_1500_fs.h5
diff --git a/tests/other_codes/vs_GprMax_oldCcode/antenna_MALA_1200_fs/antenna_MALA_1200_fs.out b/tests/other_codes/vs_GprMax_oldCcode/antenna_MALA_1200_fs/antenna_MALA_1200_fs.h5
similarity index 100%
rename from tests/other_codes/vs_GprMax_oldCcode/antenna_MALA_1200_fs/antenna_MALA_1200_fs.out
rename to tests/other_codes/vs_GprMax_oldCcode/antenna_MALA_1200_fs/antenna_MALA_1200_fs.h5
diff --git a/tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_dispersive/hertzian_dipole_dispersive.out b/tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_dispersive/hertzian_dipole_dispersive.h5
similarity index 100%
rename from tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_dispersive/hertzian_dipole_dispersive.out
rename to tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_dispersive/hertzian_dipole_dispersive.h5
diff --git a/tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_fs/hertzian_dipole_fs.out b/tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_fs/hertzian_dipole_fs.h5
similarity index 100%
rename from tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_fs/hertzian_dipole_fs.out
rename to tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_fs/hertzian_dipole_fs.h5
diff --git a/tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_hs/hertzian_dipole_hs.out b/tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_hs/hertzian_dipole_hs.h5
similarity index 100%
rename from tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_hs/hertzian_dipole_hs.out
rename to tests/other_codes/vs_GprMax_oldCcode/hertzian_dipole_hs/hertzian_dipole_hs.h5
diff --git a/tests/other_codes/vs_MoM_MATLAB/antenna_bowtie_fs/antenna_bowtie_fs.out b/tests/other_codes/vs_MoM_MATLAB/antenna_bowtie_fs/antenna_bowtie_fs.h5
similarity index 100%
rename from tests/other_codes/vs_MoM_MATLAB/antenna_bowtie_fs/antenna_bowtie_fs.out
rename to tests/other_codes/vs_MoM_MATLAB/antenna_bowtie_fs/antenna_bowtie_fs.h5