diff --git a/payments_payu/provider.py b/payments_payu/provider.py
index 1f84a89..9387325 100644
--- a/payments_payu/provider.py
+++ b/payments_payu/provider.py
@@ -340,7 +340,7 @@ def post_request(self, url, *args, **kwargs):
             kwargs["headers"] = self.get_token_headers()
             response = requests.post(url, *args, **kwargs)
             response_dict = json.loads(response.text)
-            if (
+            if (response_dict.get("error") == "invalid_token") or (
                 "status" in response_dict
                 and "statusCode" in response_dict["status"]
                 and response_dict["status"]["statusCode"] == "UNAUTHORIZED"
diff --git a/tests/test_payu.py b/tests/test_payu.py
index 7719708..1cb9441 100644
--- a/tests/test_payu.py
+++ b/tests/test_payu.py
@@ -491,6 +491,34 @@ def test_redirect_payu_unauthorized_status(self):
                 headers={"Content-Type": "application/x-www-form-urlencoded"},
             )
 
+    def test_redirect_payu_unauthorized_error(self):
+        self.set_up_provider(
+            True, False, get_refund_description=lambda payment, amount: "test"
+        )
+
+        with patch("requests.post") as mocked_post:
+            mocked_post.return_value = MagicMock(
+                status_code=401,
+                text='{"error": "invalid_token", "error_description": "Access token expired"}',
+            )
+
+            with self.assertRaisesRegex(
+                PayuApiError,
+                r"^Unable to regain authorization token "
+                r"\{'error': 'invalid_token', 'error_description': 'Access token expired'}$",
+            ):
+                self.provider.get_form(payment=self.payment)
+
+        mocked_post.assert_called_with(
+            "http://mock.url/pl/standard/user/oauth/authorize",
+            data={
+                "grant_type": "client_credentials",
+                "client_id": "123abc",
+                "client_secret": "123abc",
+            },
+            headers={"Content-Type": "application/x-www-form-urlencoded"},
+        )
+
     def test_get_access_token_trusted_merchant(self):
         self.set_up_provider(
             True, False, get_refund_description=lambda payment, amount: "test"