diff --git a/interfaces/cython/cantera/test/test_convert.py b/interfaces/cython/cantera/test/test_convert.py
index 65c60647a..b855ee7e8 100644
--- a/interfaces/cython/cantera/test/test_convert.py
+++ b/interfaces/cython/cantera/test/test_convert.py
@@ -324,3 +324,11 @@ class CtmlConverterTest(utilities.CanteraTest):
     def test_pdep(self):
         gas = ct.Solution('../data/pdep-test.cti')
         self.assertEqual(gas.n_reactions, 6)
+
+    def test_invalid(self):
+        try:
+            gas = ct.Solution('../data/invalid.cti')
+        except RuntimeError as e:
+            err = e
+
+        self.assertIn('Multiply-declared species', err.args[0])
diff --git a/test/data/invalid.cti b/test/data/invalid.cti
new file mode 100644
index 000000000..fcc231734
--- /dev/null
+++ b/test/data/invalid.cti
@@ -0,0 +1,6 @@
+ideal_gas(
+    name="complete",
+    elements=" C H O",
+    species="gri30: O2 CH4 H2O CO2 CH4",
+    initial_state=state(temperature=298.0,
+                        pressure = 100000.0))