diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
index ebba09e..d5c7dc7 100644
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -104,11 +104,15 @@ jobs:
         run: pip install dist/[Gg]722*.gz
         shell: bash
 
-      - if: ${{ matrix.os != 'windows' }}
-        name: test
+      - name: test
+        if: ${{ matrix.os != 'windows' }}
         run: ./scripts/do-test.sh "python test.py"
         shell: bash
 
+      - name: unit tests
+        run: python -m unittest discover tests '*.py'
+        shell: bash
+
   publish_wheels:
     needs: [build_and_test_python, build_in_docker]
     if: github.event_name == 'release' && github.event.action == 'created'
diff --git a/tests/test_decode.py b/tests/test_decode.py
new file mode 100644
index 0000000..2d84e11
--- /dev/null
+++ b/tests/test_decode.py
@@ -0,0 +1,22 @@
+import unittest
+
+from G722 import G722
+
+class TestDecoder(unittest.TestCase):
+    def test_decode_len(self):
+        bitrates = [48000, 56000, 64000]
+        sample_rates = [8000, 16000]
+
+        for bitrate in bitrates:
+            for sample_rate in sample_rates:
+                with self.subTest(bitrate=bitrate, sample_rate=sample_rate):
+                    g722 = G722(sample_rate, bitrate)
+                    encoded_data = b"0123"  # Example encoded data
+                    decoded_data = g722.decode(encoded_data)
+                    got = len(decoded_data)
+                    want = 4 if sample_rate == 8000 else 8
+                    self.assertEqual(want, got)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/tests/test_encode.py b/tests/test_encode.py
new file mode 100644
index 0000000..667b87c
--- /dev/null
+++ b/tests/test_encode.py
@@ -0,0 +1,21 @@
+import unittest
+
+from G722 import G722
+
+class TestEncoder(unittest.TestCase):
+    def test_encode_len(self):
+        bitrates = [48000, 56000, 64000]
+        sample_rates = [8000, 16000]
+
+        for bitrate in bitrates:
+            for sample_rate in sample_rates:
+                with self.subTest(bitrate=bitrate, sample_rate=sample_rate):
+                    g722 = G722(sample_rate, bitrate)
+                    audio_data = b"\x00\x01\x02\x03"  # Example raw audio data
+                    encoded_data = g722.encode(audio_data)
+                    got = len(encoded_data)
+                    want = 4 if sample_rate == 8000 else 2
+                    self.assertEqual(want, got)
+
+if __name__ == '__main__':
+    unittest.main()