diff --git a/scripts/ci/materialize_base_python_requirements.py b/scripts/ci/materialize_base_python_requirements.py
index 98cdad459..45d70ec0b 100755
--- a/scripts/ci/materialize_base_python_requirements.py
+++ b/scripts/ci/materialize_base_python_requirements.py
@@ -19,6 +19,7 @@
 import sys
 import tarfile
 import tempfile
+import urllib.error
 import urllib.parse
 import urllib.request
 from typing import Any
@@ -65,8 +66,14 @@ def redirect_request(
         new_url: str,
     ) -> None:
         """Fail closed for all redirect status codes and target locations."""
-        del request, response, code, message, headers, new_url
-        raise RuntimeError("trusted uv archive redirects are forbidden")
+        del message, new_url
+        raise urllib.error.HTTPError(
+            request.full_url,  # type: ignore
+            code,
+            "trusted uv archive redirects are forbidden",
+            headers,
+            response,
+        )
 
 
 @functools.cache
diff --git a/tests/test_uv_redirect_boundary.py b/tests/test_uv_redirect_boundary.py
index fd98592e8..be36f0bc7 100644
--- a/tests/test_uv_redirect_boundary.py
+++ b/tests/test_uv_redirect_boundary.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import urllib.error
 import urllib.request
 from collections.abc import Iterator
 
@@ -23,7 +24,7 @@ def test_trusted_uv_redirect_handler_rejects_before_following() -> None:
     handler = materializer._RejectTrustedUvRedirects()
     original = urllib.request.Request(materializer.TRUSTED_UV_ARCHIVE_URL)
 
-    with pytest.raises(RuntimeError, match="redirects are forbidden"):
+    with pytest.raises(urllib.error.HTTPError, match="trusted uv archive redirects are forbidden"):
         handler.redirect_request(
             original,
             None,