diff --git a/campus_python/json_client/__init__.py b/campus_python/json_client/__init__.py
index 3797fae..46d4ce5 100644
--- a/campus_python/json_client/__init__.py
+++ b/campus_python/json_client/__init__.py
@@ -13,10 +13,17 @@
 from collections.abc import Callable
 from typing import Any, Mapping, Self, cast
 
-import campus.model
 import requests
 from campus.common import env
 
+try:
+    from campus.webauth.models import HttpHeader
+except ImportError:
+    # campus-suite predating campus#857 keeps header models in
+    # campus.model; this fallback lets this client work against both
+    # the old and the new campus-suite until locks are re-resolved.
+    from campus.model import HttpHeader
+
 from .. import errors
 from .interface import JsonClient, JsonDict, JsonResponse
 
@@ -47,7 +54,7 @@ def text(self) -> str:
     def json(self) -> Any:
         try:
             return self._response.json()
-        except ValueError as exc:  # JSON decoding error
+        except ValueError:  # JSON decoding error
             raise errors.MalformedResponseError(
                 error_description="Response is not valid JSON"
             ) from None
@@ -108,10 +115,10 @@ def __init__(
             self.reset_authorization()
 
     @property
-    def headers(self) -> campus.model.HttpHeader:
+    def headers(self) -> HttpHeader:
         """Get the currently configured headers."""
         headers = cast(Mapping[str, str], self._session.headers)
-        return campus.model.HttpHeader.from_header(headers)
+        return HttpHeader.from_header(headers)
 
     def _build_url(self, path: str) -> str:
         if not self.base_url:  # relative URL