diff --git a/tests/test_ndarray.py b/tests/test_ndarray.py
index 73abedf..7be03bb 100644
--- a/tests/test_ndarray.py
+++ b/tests/test_ndarray.py
@@ -172,6 +172,18 @@ def test_ndarray_coercion():
         amod = Model(array=["a", "b", "c"])
 
 
+@pytest.mark.shape
+def test_shape_ellipsis():
+    """
+    Test that ellipsis is a wildcard, rather than "repeat the last index"
+    """
+
+    class MyModel(BaseModel):
+        array: NDArray[Shape["1, 2, ..."], Number]
+
+    _ = MyModel(array=np.zeros((1, 2, 3, 4, 5)))
+
+
 @pytest.mark.serialization
 def test_ndarray_serialize():
     """
diff --git a/tests/test_serialization.py b/tests/test_serialization.py
index 569168c..dc0ef06 100644
--- a/tests/test_serialization.py
+++ b/tests/test_serialization.py
@@ -12,6 +12,8 @@ from typing import Callable
 import numpy as np
 import json
 
+pytestmark = pytest.mark.serialization
+
 
 @pytest.fixture(scope="module")
 def hdf5_at_path() -> Callable[[Path], None]: