diff --git a/extensions/chaeo/products.py b/extensions/chaeo/products.py
index 88d8f3fa21c817170257e17286c059efead28068..d2a372b00ee8fc17afda761121e7dc9d3dcc9a1a 100644
--- a/extensions/chaeo/products.py
+++ b/extensions/chaeo/products.py
@@ -77,6 +77,6 @@ def export_patches_from_zstack(
 
         ext = 'tif' if make_3d else 'png'
         fname = f'{prefix}-la{obj.label:04d}-zi{obj.zi:04d}.{ext}'
-        success = _write_patch_to_file(where, fname, resample_to_8bit(patch))
+        _write_patch_to_file(where, fname, resample_to_8bit(patch))
         exported.append(fname)
-    return success, exported
+    return exported
diff --git a/extensions/chaeo/tests/test_zstack.py b/extensions/chaeo/tests/test_zstack.py
index 8ea85d796ade56ee2f3dc3905055cc2496c3705c..6c398d24b99dbe1d6874cc3b742e92a0a23cad16 100644
--- a/extensions/chaeo/tests/test_zstack.py
+++ b/extensions/chaeo/tests/test_zstack.py
@@ -67,13 +67,12 @@ class TestZStackDerivedDataProducts(unittest.TestCase):
             filters={'area': (1e3, 1e4)},
             expand_box_by=(64, 2)
         )
-        success, files = export_patches_from_zstack(
+        files = export_patches_from_zstack(
             output_path / '2d_patches',
             self.stack.get_one_channel_data(channel=1),
             meta,
             draw_bounding_box=True,
         )
-        self.assertTrue(success)
         self.assertGreaterEqual(len(files), 1)
 
     def test_make_3d_patches_from_zmask(self):
@@ -81,11 +80,10 @@ class TestZStackDerivedDataProducts(unittest.TestCase):
             filters={'area': (1e3, 1e4)},
             expand_box_by=(64, 2),
         )
-        success, files = export_patches_from_zstack(
+        files = export_patches_from_zstack(
             output_path / '3d_patches',
             self.stack.get_one_channel_data(channel=1),
             meta,
             make_3d=True)
-        self.assertTrue(success)
         self.assertGreaterEqual(len(files), 1)