diff --git a/src/openeo_processes/cubes.py b/src/openeo_processes/cubes.py
index be532686..8a8e1481 100644
--- a/src/openeo_processes/cubes.py
+++ b/src/openeo_processes/cubes.py
@@ -677,7 +677,7 @@ def refactor_data(data: xr.DataArray) -> List[xr.Dataset]:
         def create_output_filepath(output_filepath: str, idx: int = 0, ext: str = "nc") -> str:
             """Create the output filepath."""
             root, _ = splitext(output_filepath)
-            return f'{root}_{idx}.{ext}'
+            return f'{root}_{str(idx).zfill(5)}.{ext}'
 
         # start workaround
         # https://github.com/opendatacube/datacube-core/issues/972
diff --git a/tests/test_cubes.py b/tests/test_cubes.py
index 1e4a34eb..999582de 100644
--- a/tests/test_cubes.py
+++ b/tests/test_cubes.py
@@ -56,8 +56,8 @@ def test_save_result(self):
         # TODO improve file check
         # xarray tests
         out_filename = "out.tif"
-        out_filename_0 = "out_0.tif"
-        out_filename_1 = "out_1.tif"
+        out_filename_0 = "out_00000.tif"
+        out_filename_1 = "out_00001.tif"
         out_product = "product.yml"
         oeop.save_result(self.test_data.xr_odc_data_3d, out_filename)
         assert os.path.exists(out_filename_0)
@@ -74,8 +74,8 @@ def test_save_result(self):
         os.remove(out_product)
 
         out_filename = "out.nc"
-        out_filename_0 = "out_0.nc"
-        out_filename_1 = "out_1.nc"
+        out_filename_0 = "out_00000.nc"
+        out_filename_1 = "out_00001.nc"
 
         oeop.save_result(self.test_data.xr_data_extra_dim, out_filename, format='netCDF', write_prod=False)
         assert os.path.exists(out_filename_0)
@@ -107,14 +107,14 @@ def test_save_result_from_file(self):
         ref_ds_0 = ref_ds.loc[dict(time="2016-01-13T12:00:00.000000000")]
         data_array = ref_ds.to_array(dim="bands")
         oeop.save_result(data_array, format='netCDF')
-        actual_ds_0 = xr.load_dataset("out_0.nc")
+        actual_ds_0 = xr.load_dataset("out_00000.nc")
         assert ref_ds_0.dims == actual_ds_0.dims
         assert ref_ds_0.coords == actual_ds_0.coords
         assert ref_ds_0.variables == actual_ds_0.variables
         assert ref_ds_0.geobox == actual_ds_0.geobox
         assert ref_ds_0.extent == actual_ds_0.extent
         for i in range(10):
-            os.remove(f"out_{i}.nc")
+            os.remove(f"out_{str(i).zfill(5)}.nc")
         os.remove("product.yml")
 
     def test_fit_curve(self):