diff --git a/requests_oauth2client/client.py b/requests_oauth2client/client.py
index e9cca21..cdaba8f 100644
--- a/requests_oauth2client/client.py
+++ b/requests_oauth2client/client.py
@@ -305,7 +305,7 @@ class OAuth2Client:
     extra_metadata: dict[str, Any] = field(factory=dict)
     testing: bool = False
 
-    bearer_token_class: type[BearerToken] = BearerToken
+    token_class: type[BearerToken] = BearerToken
 
     exception_classes: ClassVar[dict[str, type[EndpointError]]] = {
         "server_error": ServerError,
@@ -348,7 +348,7 @@ def __init__(  # noqa: PLR0913
         id_token_decryption_key: Jwk | dict[str, Any] | None = None,
         code_challenge_method: str = CodeChallengeMethods.S256,
         authorization_response_iss_parameter_supported: bool = False,
-        bearer_token_class: type[BearerToken] = BearerToken,
+        token_class: type[BearerToken] = BearerToken,
         session: requests.Session | None = None,
         testing: bool = False,
         **extra_metadata: Any,
@@ -402,8 +402,8 @@ def __init__(  # noqa: PLR0913
             id_token_decryption_key=id_token_decryption_key,
             code_challenge_method=code_challenge_method,
             authorization_response_iss_parameter_supported=authorization_response_iss_parameter_supported,
-            bearer_token_class=bearer_token_class,
             extra_metadata=extra_metadata,
+            token_class=token_class,
         )
 
     @token_endpoint.validator
@@ -565,7 +565,7 @@ def parse_token_response(self, response: requests.Response) -> BearerToken:
 
         """
         try:
-            token_response = self.bearer_token_class(**response.json())
+            token_response = self.token_class(**response.json())
         except Exception:  # noqa: BLE001
             return self.on_token_error(response)
         else:
@@ -623,7 +623,7 @@ def client_credentials(
             **token_kwargs: additional parameters for the token endpoint, alongside `grant_type`. Common parameters
 
         Returns:
-            a TokenResponse
+            a BearerToken
 
         Raises:
             InvalidScopeParam: if the `scope` parameter is not suitable
diff --git a/requests_oauth2client/tokens.py b/requests_oauth2client/tokens.py
index ceed139..517edc6 100644
--- a/requests_oauth2client/tokens.py
+++ b/requests_oauth2client/tokens.py
@@ -229,6 +229,7 @@ class BearerToken(TokenResponse, requests.auth.AuthBase):
     """
 
     TOKEN_TYPE: ClassVar[str] = AccessTokenType.BEARER.value
+    AUTHORIZATION_HEADER: ClassVar[str] = "Authorization"
 
     access_token: str
     expires_at: datetime | None = None
@@ -540,7 +541,7 @@ def __call__(self, request: requests.PreparedRequest) -> requests.PreparedReques
             return request  # pragma: no cover
         if self.is_expired():
             raise ExpiredAccessToken(self)
-        request.headers["Authorization"] = self.authorization_header()
+        request.headers[self.AUTHORIZATION_HEADER] = self.authorization_header()
         return request
 
 
@@ -626,7 +627,3 @@ def loads(self, serialized: str) -> BearerToken:
 
         """
         return self.loader(serialized)
-
-
-class DPoPToken(TokenResponse):
-    """Represents a DPoP Token."""
diff --git a/tests/unit_tests/test_client.py b/tests/unit_tests/test_client.py
index e2b7efb..5f56854 100644
--- a/tests/unit_tests/test_client.py
+++ b/tests/unit_tests/test_client.py
@@ -1423,7 +1423,7 @@ def test_custom_token_type(requests_mock: RequestsMocker, token_endpoint: str) -
     class CustomBearerToken(BearerToken):
         TOKEN_TYPE = "CustomBearerToken"
 
-    client = OAuth2Client(token_endpoint, ("client_id", "client_secret"), bearer_token_class=CustomBearerToken)
+    client = OAuth2Client(token_endpoint, ("client_id", "client_secret"), token_class=CustomBearerToken)
 
     requests_mock.post(
         token_endpoint,
@@ -1532,3 +1532,17 @@ def test_testing_oauth2client() -> None:
 
     assert test_client.token_endpoint == token_endpoint
     assert test_client.issuer == issuer
+
+
+def test_proxy_authorization(requests_mock: RequestsMocker, target_api: str) -> None:
+    access_token = "my_proxy_auth_token"
+    auth_header = "Proxy-Authorization"
+
+    class ProxyAuthorizationBearerToken(BearerToken):
+        AUTHORIZATION_HEADER = auth_header
+
+    requests_mock.post(target_api)
+
+    requests.post(target_api, auth=ProxyAuthorizationBearerToken(access_token))
+    assert requests_mock.last_request is not None
+    assert requests_mock.last_request.headers[auth_header] == f"Bearer {access_token}"