diff --git a/tests/test_units.py b/tests/test_units.py
index 7fc4783..30faaa7 100644
--- a/tests/test_units.py
+++ b/tests/test_units.py
@@ -76,6 +76,7 @@ def test_can_read_units(test_input):
 
 @pytest.mark.parametrize("test_input", units_with_chemical_element)
 def test_handle_chemicals(test_input):
+    """Ensures the unit registry can add new units when parsed by ``handle_chemicals``."""
     handle_chemicals(test_input)
     ureg(test_input)