diff --git a/lib/extract.py b/lib/extract.py
index d82de83..17d3e7a 100644
--- a/lib/extract.py
+++ b/lib/extract.py
@@ -483,7 +483,7 @@ async def _extract_one_source(
         if not target or not evidence:
             continue
         # Find the target claim file in the worktree (search domains/)
-        target_stem = target.replace(".md", "")
+        target_stem = Path(target.replace(".md", "")).name
         found = None
         for domain_dir in (worktree / "domains").iterdir():
             candidate = domain_dir / f"{target_stem}.md"