diff --git a/model_server/base/accessors.py b/model_server/base/accessors.py
index f7d076fa7653faf7fbf22d8a2ff7577228ab2420..6ccd74b7833092473b444bf66aaca9593f75fe2e 100644
--- a/model_server/base/accessors.py
+++ b/model_server/base/accessors.py
@@ -88,7 +88,7 @@ class GenericImageDataAccessor(ABC):
     def _gc(self, channels):
         return self.get_channels(list(channels))
 
-    def _unique(self):
+    def unique(self):
         return np.unique(self.data, return_counts=True)
 
     @property
diff --git a/tests/test_ilastik/test_ilastik.py b/tests/test_ilastik/test_ilastik.py
index b6a6f851f6cb674e29b904470a28b0b4100f3966..9e2bbd3d42a4a0fdbf65b553852aa4b26cb94e91 100644
--- a/tests/test_ilastik/test_ilastik.py
+++ b/tests/test_ilastik/test_ilastik.py
@@ -382,7 +382,7 @@ class TestIlastikOnMultichannelInputs(conf.TestServerBaseClass):
         acc_input = generate_file_accessor(self.pa_input_image)
         acc_obmap = res['ob_map']
         self.assertEqual(acc_obmap.hw, acc_input.hw)
-        self.assertEqual(len(acc_obmap._unique()[1]), 3)
+        self.assertEqual(len(acc_obmap.unique()[1]), 3)
 
 
     def test_api(self):
diff --git a/tests/test_ilastik/test_roiset_workflow.py b/tests/test_ilastik/test_roiset_workflow.py
index 19c7d9f78aa97f22ac46c79f76c380a762b93ecf..4d8d4ec3885402eb1ba1e3ab48124ac72693774b 100644
--- a/tests/test_ilastik/test_roiset_workflow.py
+++ b/tests/test_ilastik/test_roiset_workflow.py
@@ -119,9 +119,9 @@ class TestRoiSetWorkflow(BaseTestRoiSetMonoProducts, unittest.TestCase):
 
         trace.write_interm(Path(output_path) / 'trace', 'roiset_worfklow_trace', skip_first=False, skip_last=False)
         self.assertTrue('ob_id' in trace.keys())
-        self.assertEqual(len(trace['labeled']._unique()[0]), 14)
+        self.assertEqual(len(trace['labeled'].unique()[0]), 14)
         self.assertEqual(rois.count, 13)
-        self.assertEqual(len(trace['ob_id']._unique()[0]), 2)
+        self.assertEqual(len(trace['ob_id'].unique()[0]), 2)
 
 
 class TestRoiSetWorkflowOverApi(conf.TestServerBaseClass, BaseTestRoiSetMonoProducts):
@@ -183,8 +183,8 @@ class TestRoiSetWorkflowOverApi(conf.TestServerBaseClass, BaseTestRoiSetMonoProd
 
     def test_workflow_with_object_classifier(self):
         acc = self._object_map_workflow(self.test_load_object_classifier())
-        self.assertTrue(np.all(acc._unique()[0] == [0, 1, 2]))
+        self.assertTrue(np.all(acc.unique()[0] == [0, 1, 2]))
 
     def test_workflow_without_object_classifier(self):
         acc = self._object_map_workflow(None)
-        self.assertTrue(np.all(acc._unique()[0] == [0, 1]))
+        self.assertTrue(np.all(acc.unique()[0] == [0, 1]))