diff --git a/django_altcha/__init__.py b/django_altcha/__init__.py
index 83c23ce..256c1c8 100644
--- a/django_altcha/__init__.py
+++ b/django_altcha/__init__.py
@@ -60,14 +60,14 @@ def mark_challenge_used(challenge, timeout):
 
 def get_altcha_challenge(max_number=None, expires=None):
     """
-    Generate and return an ALTCHA challenge.
+    Generate and return an ALTCHA v1 challenge.
 
     Attributes:
         max_number (int): Maximum number to use for the challenge.
         expires (int): Expiration time for the challenge in milliseconds.
 
     Returns:
-        altcha.Challenge: The generated challenge.
+        altcha.ChallengeV1: The generated challenge.
     """
     expires = expires or get_setting("ALTCHA_CHALLENGE_EXPIRE")
     options = {
@@ -78,7 +78,7 @@ def get_altcha_challenge(max_number=None, expires=None):
     if max_number is not None:
         options["max_number"] = max_number
 
-    challenge = altcha.create_challenge(altcha.ChallengeOptions(**options))
+    challenge = altcha.create_challenge_v1(altcha.ChallengeOptionsV1(**options))
     return challenge
 
 
@@ -246,7 +246,7 @@ def validate(self, value):
             )
 
         try:
-            verified, error = altcha.verify_solution(
+            verified, error = altcha.verify_solution_v1(
                 payload=value,
                 hmac_key=get_hmac_key(),
                 check_expires=True,
diff --git a/pyproject.toml b/pyproject.toml
index b54d96c..14b5d2b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ classifiers = [
 requires-python = ">=3.9"
 dependencies = [
     "Django>=4.2",
-    "altcha>=1.0.0,<2.0.0",
+    "altcha>=2.0.0,<3.0.0",
 ]
 keywords = ["captcha", "django", "widget", "form", "altcha"]
 
diff --git a/tests/test_field.py b/tests/test_field.py
index eb736ce..7002c01 100644
--- a/tests/test_field.py
+++ b/tests/test_field.py
@@ -60,7 +60,7 @@ def test_altcha_field_with_missing_value_raises_required_error(self):
             form.errors["altcha_field"][0], "ALTCHA CAPTCHA token is missing."
         )
 
-    @mock.patch("altcha.verify_solution")
+    @mock.patch("altcha.verify_solution_v1")
     def test_altcha_field_validation_calls_verify_solution(self, mock_verify_solution):
         self.assertFalse(is_challenge_used(TEST_CHALLENGE))
         mock_verify_solution.return_value = (True, None)
@@ -81,7 +81,7 @@ def test_altcha_field_validation_calls_verify_solution(self, mock_verify_solutio
             form.errors["altcha_field"][0], "Challenge has already been used."
         )
 
-    @mock.patch("altcha.verify_solution")
+    @mock.patch("altcha.verify_solution_v1")
     def test_altcha_field_validation_fails_on_invalid_token(self, mock_verify_solution):
         mock_verify_solution.return_value = (False, "Invalid token")
         form = self.form_class(data={"altcha_field": "invalid_token"})
@@ -89,7 +89,7 @@ def test_altcha_field_validation_fails_on_invalid_token(self, mock_verify_soluti
         self.assertIn("altcha_field", form.errors)
         self.assertEqual(form.errors["altcha_field"][0], "Invalid CAPTCHA token.")
 
-    @mock.patch("altcha.verify_solution")
+    @mock.patch("altcha.verify_solution_v1")
     def test_altcha_field_validation_handles_exception(self, mock_verify_solution):
         mock_verify_solution.side_effect = Exception("Verification failed")
         form = self.form_class(data={"altcha_field": "some_token"})
diff --git a/tests/test_logging.py b/tests/test_logging.py
index fbe1857..1571a30 100644
--- a/tests/test_logging.py
+++ b/tests/test_logging.py
@@ -24,7 +24,7 @@ class TestForm(forms.Form):
 
         self.form_class = TestForm
 
-    @mock.patch("altcha.verify_solution")
+    @mock.patch("altcha.verify_solution_v1")
     def test_invalid_token_logs_warning(self, mock_verify_solution):
         mock_verify_solution.return_value = (False, "bad signature")
         form = self.form_class(data={"altcha_field": "anything"})
@@ -34,7 +34,7 @@ def test_invalid_token_logs_warning(self, mock_verify_solution):
         self.assertEqual(captured.records[0].levelname, "WARNING")
         self.assertIn("bad signature", captured.output[0])
 
-    @mock.patch("altcha.verify_solution")
+    @mock.patch("altcha.verify_solution_v1")
     def test_verification_exception_is_logged_with_traceback(
         self, mock_verify_solution
     ):
@@ -46,7 +46,7 @@ def test_verification_exception_is_logged_with_traceback(
         # Confirms traceback is captured
         self.assertIsNotNone(captured.records[0].exc_info)
 
-    @mock.patch("altcha.verify_solution")
+    @mock.patch("altcha.verify_solution_v1")
     def test_replay_attempt_logs_warning(self, mock_verify_solution):
         mock_verify_solution.return_value = (True, None)
         valid_payload = make_valid_payload(challenge="replay-test-1")