diff --git a/extensions/chaeo/conf/testing.py b/extensions/chaeo/conf/testing.py
index 81a0ba82d42dfdcbd950acdab6f72d71b7b54bc9..4ca906805e02919cd55dce69c0fea5d9e2b7abc2 100644
--- a/extensions/chaeo/conf/testing.py
+++ b/extensions/chaeo/conf/testing.py
@@ -3,10 +3,10 @@ from pathlib import Path
 root = Path.home() / 'model-server'
 
 multichannel_zstack = {
-    'path': root / 'testing' / 'zmask-test-stack.tif',
+    'path': root / 'testing' / 'zmask-test-stack-chlorophyl.tif',
     'w': 512,
     'h': 512,
-    'c': 2,
+    'c': 5,
     'z': 7,
 }
 
diff --git a/extensions/chaeo/tests/test_zstack.py b/extensions/chaeo/tests/test_zstack.py
index c2d0b1136ad8a3c3f99c4611c57fb12d04664740..92d3ef25cbed65fa02e047f21d209ae66f829bb8 100644
--- a/extensions/chaeo/tests/test_zstack.py
+++ b/extensions/chaeo/tests/test_zstack.py
@@ -86,7 +86,7 @@ class TestZStackDerivedDataProducts(unittest.TestCase):
         )
         files = export_patches_from_zstack(
             output_path / '3d_patches',
-            self.stack.get_one_channel_data(channel=1),
+            self.stack.get_one_channel_data(4),
             meta,
             make_3d=True)
         self.assertGreaterEqual(len(files), 1)
@@ -94,7 +94,7 @@ class TestZStackDerivedDataProducts(unittest.TestCase):
     def test_flatten_image(self):
         zmask, meta, df, interm = build_zmask_from_object_mask(
             self.obmap.get_one_channel_data(0),
-            self.stack.get_one_channel_data(1),
+            self.stack.get_one_channel_data(4),
             mask_type='boxes',
         )