diff --git a/zahlwort2num/__init__.py b/zahlwort2num/__init__.py
index cacf7d9..2e0a2b5 100644
--- a/zahlwort2num/__init__.py
+++ b/zahlwort2num/__init__.py
@@ -12,6 +12,7 @@ class ZahlConverter:
         'eine': 1,
         'er': 1,
         'zwei': 2,
+        'zwo': 2,
         'drei': 3,
         'drit': 3,
         'vier': 4,

diff --git a/zahlwort2num/tests/test_convert.py b/zahlwort2num/tests/test_convert.py
index 91fd15f..905ec5c 100644
--- a/zahlwort2num/tests/test_convert.py
+++ b/zahlwort2num/tests/test_convert.py
@@ -6,6 +6,7 @@ class TestConverter(TestCase):
     def test_hardcoded_values_upto_100(self):
         self.assertTrue(w2n.convert('eins') == 1)
         self.assertTrue(w2n.convert('zwei') == 2)
+        self.assertTrue(w2n.convert('zwo') == 2)
         self.assertTrue(w2n.convert('drei') == 3)
         self.assertTrue(w2n.convert('vier') == 4)
         self.assertTrue(w2n.convert('fünf') == 5)
@@ -128,12 +129,14 @@ class TestConverter(TestCase):
                  'zwei milliarden',
                  'eintausend',
                  'null',
-                 'neunundvierzig'
+                 'neunundvierzig',
+                 'zwohundertzwoundzwanzig',
+                 'zwotausend'
                  ]
 
         numbers = [7, 99, 1000, 200000, 4504, 4511, 225, 3625, 12854, 653521,
                    99, 500002, 1004000, 700000000009001009001, 9000000000000000000000000011,
-                   2000000000, 1000, 0, 49]
+                   2000000000, 1000, 0, 49, 222, 2000]
 
         self.compare_sets(numbers, words)
 

Does not work with alternative pronunciation "zwo"
```py
>>> from zahlwort2num import convert
>>> convert("zwo")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 137, in convert
    return c.convert()
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 123, in convert
    return self.ordBn(number)
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 108, in ordBn
    return self.ordWithBN(number, 0)
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 88, in ordWithBN
    return self.convOrd(number)
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 81, in convOrd
    return self.convt2(number)
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 129, in <lambda>
    self.convt2 = lambda number: self.mult(number, 'tausend', 1000, self.convh2)
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 60, in mult
    return fun(spliter[0])
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 130, in <lambda>
    self.convh2 = lambda number: self.mult(number, 'hundert', 100, self.convu2)
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 60, in mult
    return fun(spliter[0])
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 131, in <lambda>
    self.convu2 = lambda number: self.mult(number, 'und', 1, lambda word: self.CONST_NUMS[word])
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 60, in mult
    return fun(spliter[0])
  File "C:\ProgramData\miniforge3\lib\site-packages\zahlwort2num\__init__.py", line 131, in <lambda>
    self.convu2 = lambda number: self.mult(number, 'und', 1, lambda word: self.CONST_NUMS[word])
KeyError: 'zwo'
```
zahlwort2num/tests/test_convert.py::TestConverter::test_hardcoded_values_upto_100 zahlwort2num/tests/test_convert.py::TestConverter::test_more_specific
zahlwort2num/tests/test_convert.py::TestConverter::test_bugs_found_by_users zahlwort2num/tests/test_convert.py::TestConverter::test_negative_values zahlwort2num/tests/test_convert.py::TestConverter::test_negative_with_ordinal zahlwort2num/tests/test_convert.py::TestConverter::test_ordinal_numbers zahlwort2num/tests/test_convert.py::TestConverter::test_swiss_variant zahlwort2num/tests/test_convert.py::TestConverter::test_yet_another_ordinal_edge_case