diff --git a/src/secops/auth.py b/src/secops/auth.py
index 2d34954..c7492c7 100644
--- a/src/secops/auth.py
+++ b/src/secops/auth.py
@@ -188,7 +188,11 @@ def _get_credentials(
         """Get credentials from various sources."""
         try:
             if credentials:
-                google_credentials = credentials.with_scopes(self.scopes)
+                if hasattr(credentials, "with_scopes"):
+                    google_credentials = credentials.with_scopes(self.scopes)
+                else:
+                    # Assume credentials are already scoped
+                    google_credentials = credentials
 
             elif service_account_info:
                 google_credentials = (
diff --git a/tests/test_auth.py b/tests/test_auth.py
index a6d6fe2..4164bdb 100644
--- a/tests/test_auth.py
+++ b/tests/test_auth.py
@@ -73,3 +73,16 @@ def test_custom_user_agent():
     assert session is not None
     assert hasattr(session, "headers")
     assert session.headers.get("User-Agent") == "secops-wrapper-sdk"
+
+
+def test_bearer_token_credentials_accepted():
+    """Test scope passed for token credentials"""
+    from google.oauth2.credentials import Credentials as OAuthCredentials
+
+    creds = OAuthCredentials(token="fake-bearer-token")
+    assert not hasattr(creds, "with_scopes"), (
+        "Test assumption broken: OAuthCredentials now has with_scopes"
+    )
+
+    auth = SecOpsAuth(credentials=creds)
+    assert auth.credentials is creds
\ No newline at end of file