diff --git a/tests/test_apply_workflow.py b/tests/test_apply_workflow.py
index a7e6444..c2662d0 100644
--- a/tests/test_apply_workflow.py
+++ b/tests/test_apply_workflow.py
@@ -1,9 +1,7 @@
-import pytest
 from devtools import debug
 from models import Dataset
 from models import Task
 from models import WorkflowTask
-from runner import _validate_parallelization_list_valid
 from runner import apply_workflow
 
 from tests.tasks_for_tests import create_images_from_scratch
@@ -41,63 +39,3 @@ def test_single_parallel_task_no_parallization_list():
     ]
     dataset_out = apply_workflow(wf_task_list=task_list, dataset=dataset_in)
     debug(dataset_out.image_paths)
-
-
-def test_unit_validate_parallelization_list():
-
-    # Missing path
-    PARALLELIZATION_LIST = [dict()]
-    CURRENT_IMAGE_PATHS = []
-    with pytest.raises(ValueError):
-        _validate_parallelization_list_valid(
-            parallelization_list=PARALLELIZATION_LIST,
-            current_image_paths=CURRENT_IMAGE_PATHS,
-        )
-
-    # Path not in current image paths
-    PARALLELIZATION_LIST = [dict(path="asd")]
-    CURRENT_IMAGE_PATHS = []
-    with pytest.raises(ValueError):
-        _validate_parallelization_list_valid(
-            parallelization_list=PARALLELIZATION_LIST,
-            current_image_paths=CURRENT_IMAGE_PATHS,
-        )
-
-    # Invalid buffer attributes
-    PARALLELIZATION_LIST = [dict(path="asd", buffer={})]
-    CURRENT_IMAGE_PATHS = ["asd"]
-    with pytest.raises(ValueError):
-        _validate_parallelization_list_valid(
-            parallelization_list=PARALLELIZATION_LIST,
-            current_image_paths=CURRENT_IMAGE_PATHS,
-        )
-
-    # Invalid `buffer`` attribute
-    PARALLELIZATION_LIST = [dict(path="asd", buffer={})]
-    CURRENT_IMAGE_PATHS = ["asd"]
-    with pytest.raises(ValueError):
-        _validate_parallelization_list_valid(
-            parallelization_list=PARALLELIZATION_LIST,
-            current_image_paths=CURRENT_IMAGE_PATHS,
-        )
-
-    # Invalid `root_dir` attribute
-    PARALLELIZATION_LIST = [dict(path="asd", root_dir="/something")]
-    CURRENT_IMAGE_PATHS = ["asd"]
-    with pytest.raises(ValueError):
-        _validate_parallelization_list_valid(
-            parallelization_list=PARALLELIZATION_LIST,
-            current_image_paths=CURRENT_IMAGE_PATHS,
-        )
-
-    # Valid call
-    PARALLELIZATION_LIST = [
-        dict(path="asd", parameter=1),
-        dict(path="asd", parameter=2),
-        dict(path="asd", parameter=3),
-    ]
-    CURRENT_IMAGE_PATHS = ["asd"]
-    _validate_parallelization_list_valid(
-        parallelization_list=PARALLELIZATION_LIST,
-        current_image_paths=CURRENT_IMAGE_PATHS,
-    )
diff --git a/tests/test_unit_aux_functions.py b/tests/test_unit_aux_functions.py
new file mode 100644
index 0000000..47e1362
--- /dev/null
+++ b/tests/test_unit_aux_functions.py
@@ -0,0 +1,72 @@
+import pytest
+from images import _deduplicate_list_of_dicts
+from runner import _validate_parallelization_list_valid
+
+
+def test_validate_parallelization_list():
+
+    # Missing path
+    PARALLELIZATION_LIST = [dict()]
+    CURRENT_IMAGE_PATHS = []
+    with pytest.raises(ValueError):
+        _validate_parallelization_list_valid(
+            parallelization_list=PARALLELIZATION_LIST,
+            current_image_paths=CURRENT_IMAGE_PATHS,
+        )
+
+    # Path not in current image paths
+    PARALLELIZATION_LIST = [dict(path="asd")]
+    CURRENT_IMAGE_PATHS = []
+    with pytest.raises(ValueError):
+        _validate_parallelization_list_valid(
+            parallelization_list=PARALLELIZATION_LIST,
+            current_image_paths=CURRENT_IMAGE_PATHS,
+        )
+
+    # Invalid buffer attributes
+    PARALLELIZATION_LIST = [dict(path="asd", buffer={})]
+    CURRENT_IMAGE_PATHS = ["asd"]
+    with pytest.raises(ValueError):
+        _validate_parallelization_list_valid(
+            parallelization_list=PARALLELIZATION_LIST,
+            current_image_paths=CURRENT_IMAGE_PATHS,
+        )
+
+    # Invalid `buffer`` attribute
+    PARALLELIZATION_LIST = [dict(path="asd", buffer={})]
+    CURRENT_IMAGE_PATHS = ["asd"]
+    with pytest.raises(ValueError):
+        _validate_parallelization_list_valid(
+            parallelization_list=PARALLELIZATION_LIST,
+            current_image_paths=CURRENT_IMAGE_PATHS,
+        )
+
+    # Invalid `root_dir` attribute
+    PARALLELIZATION_LIST = [dict(path="asd", root_dir="/something")]
+    CURRENT_IMAGE_PATHS = ["asd"]
+    with pytest.raises(ValueError):
+        _validate_parallelization_list_valid(
+            parallelization_list=PARALLELIZATION_LIST,
+            current_image_paths=CURRENT_IMAGE_PATHS,
+        )
+
+    # Valid call
+    PARALLELIZATION_LIST = [
+        dict(path="asd", parameter=1),
+        dict(path="asd", parameter=2),
+        dict(path="asd", parameter=3),
+    ]
+    CURRENT_IMAGE_PATHS = ["asd"]
+    _validate_parallelization_list_valid(
+        parallelization_list=PARALLELIZATION_LIST,
+        current_image_paths=CURRENT_IMAGE_PATHS,
+    )
+
+
+def test_deduplicate_list_of_dicts():
+    old = [dict(a=1), dict(b=2)]
+    new = _deduplicate_list_of_dicts(old)
+    assert len(new) == 2
+    old = [dict(a=1), dict(a=1), dict(b=2), dict(a=1)]
+    new = _deduplicate_list_of_dicts(old)
+    assert len(new) == 2