diff --git a/newsfragments/337.misc b/newsfragments/337.misc
new file mode 100644
index 000000000..6f5e76d9e
--- /dev/null
+++ b/newsfragments/337.misc
@@ -0,0 +1 @@
+Add test for legacy datablock feature
diff --git a/tests/test_datablock.py b/tests/test_datablock.py
index 3b06f5e75..9b810aa6c 100644
--- a/tests/test_datablock.py
+++ b/tests/test_datablock.py
@@ -155,3 +155,19 @@ def test_with_external_lookup(centroid_test_data):
     assert imageset.external_lookup.mask.data.tile(0).data().all_eq(True)
     assert imageset.external_lookup.gain.data.tile(0).data().all_eq(1)
     assert imageset.external_lookup.pedestal.data.tile(0).data().all_eq(0)
+
+
+@pytest.mark.xfail(
+    raises=AssertionError, reason="/~https://github.com/cctbx/dxtbx/issues/336"
+)
+def test_single_image_datablock(dials_regression):
+    path = os.path.join(
+        dials_regression,
+        "image_examples",
+        "LCLS_cspad_nexus",
+        "idx-20130301060858401.cbf",
+    )
+    datablocks_cbf = DataBlockFactory.from_filenames([path])
+    datablock_cbf = datablocks_cbf[0]
+    imageset_cbf = datablock_cbf.extract_imagesets()[0]
+    assert imageset_cbf.get_detector(0) is not None