diff --git a/src/kb/storage/objects.py b/src/kb/storage/objects.py
index a11d1e5..aae93be 100644
--- a/src/kb/storage/objects.py
+++ b/src/kb/storage/objects.py
@@ -2,7 +2,7 @@
 
 Both raw files and cached parse artifacts (Unstructured element JSON) live here.
 Keying convention:
-    raw/<domain>/<content_hash>/<filename>
+    raw/<domain>/<content_hash>
     parse/<content_hash>/elements.json
 """
 
@@ -125,7 +125,7 @@ def _get_backend() -> _Backend:
 async def put_raw_file(*, domain: str, filename: str, blob: bytes) -> tuple[str, str]:
     """Store a raw upload; returns (object_key, content_hash). Idempotent by content_hash."""
     h = _content_hash(blob)
-    key = f"raw/{domain}/{h}/{filename}"
+    key = f"raw/{domain}/{h}"
     backend = _get_backend()
     if not await backend.exists(key):
         await backend.put(key, blob)
diff --git a/tests/test_objects.py b/tests/test_objects.py
new file mode 100644
index 0000000..d7837f0
--- /dev/null
+++ b/tests/test_objects.py
@@ -0,0 +1,33 @@
+"""Raw object store keying and idempotency."""
+
+from __future__ import annotations
+
+import asyncio
+import hashlib
+
+from kb.storage import objects
+
+
+class FakeBackend:
+    def __init__(self) -> None:
+        self.keys: list[str] = []
+        self._exists: set[str] = set()
+
+    async def exists(self, key: str) -> bool:
+        return key in self._exists
+
+    async def put(self, key: str, blob: bytes, mime: str | None = None) -> None:
+        self.keys.append(key)
+        self._exists.add(key)
+
+
+def test_put_raw_file_is_idempotent_by_content_hash(monkeypatch) -> None:
+    backend = FakeBackend()
+    monkeypatch.setattr(objects, "_backend", backend)
+
+    first = asyncio.run(objects.put_raw_file(domain="sec", filename="a.pdf", blob=b"same"))
+    second = asyncio.run(objects.put_raw_file(domain="sec", filename="b.pdf", blob=b"same"))
+
+    expected_key = f"raw/sec/{hashlib.sha256(b'same').hexdigest()}"
+    assert first == second
+    assert backend.keys == [expected_key]