diff --git a/tox.ini b/tox.ini
index 65e93ce00..0ebabe2c1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -48,6 +48,8 @@ markers =
     obolibrary
 filterwarnings =
     error
+    # dandi/tests/test_pynwb_utils.py::test_nwb_has_external_links
+    ignore:.*Value with data type .* is being converted:hdmf.build.warnings.DtypeConversionWarning
 
 [coverage:run]
 parallel = True