diff --git a/tests/repositories/historic_epc/test_historic_epc_s3_repository.py b/tests/repositories/historic_epc/test_historic_epc_s3_repository.py
index 509fcf0fd..96187181d 100644
--- a/tests/repositories/historic_epc/test_historic_epc_s3_repository.py
+++ b/tests/repositories/historic_epc/test_historic_epc_s3_repository.py
@@ -128,3 +128,17 @@ def test_invalid_postcode_raises_postcode_not_found():
     with patch.object(AddressMatch, "is_valid_postcode", return_value=False):
         with pytest.raises(PostcodeNotFound):
             repo.get_for_postcode("NONSENSE")
+
+
+def test_uprn_trailing_dot_zero_is_stripped():
+    # Arrange — pandas reads an integer UPRN column as float, so the CSV cell
+    # arrives as "151020766.0"; the domain UPRN must be the bare integer string.
+    df = _df([_row("47 GORDON ROAD", "151020766.0")])
+    repo = HistoricEpcS3Repository(read_csv_gz=lambda bucket, key: df)
+
+    # Act
+    with _valid_postcode():
+        records = repo.get_for_postcode("AB33 8AL")
+
+    # Assert
+    assert records[0].uprn == "151020766"