diff --git a/stringCalculator.py b/stringCalculator.py
index 8b01b3d9c67c3f9e6c7ec9d33aed66266e97a13d..417673fe09651b7415d33fe498c72fed5ebb1a86 100644
--- a/stringCalculator.py
+++ b/stringCalculator.py
@@ -144,5 +144,9 @@ class TestStringCalculator(unittest.TestCase):
         res = self.c.add(" 4  , 5")
         self.assertEqual(res, 9)
 
+    def test_multiple_num_with_thousandone(self):
+        res = self.c.add(" 2, 1001, 5")
+        self.assertEqual(res, 7)
+
 if __name__ == "__main__":
     unittest.main()
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