diff --git a/packages/agentenv-protocol/src/agentenv_protocol/website_browser/control.py b/packages/agentenv-protocol/src/agentenv_protocol/website_browser/control.py
index 8add4f5b..81666e83 100644
--- a/packages/agentenv-protocol/src/agentenv_protocol/website_browser/control.py
+++ b/packages/agentenv-protocol/src/agentenv_protocol/website_browser/control.py
@@ -617,8 +617,11 @@ def _on_Browser_downloadProgress(self, params: dict, session: Optional[str]) ->
             download["ended_at"] = _now()
 
     async def _hashed(self, download: dict, path: Path) -> None:
-        size, sha256 = await asyncio.to_thread(_size_and_sha256, path)
-        download.update(size=size, sha256=sha256, ended_at=_now())
+        try:
+            size, sha256 = await asyncio.to_thread(_size_and_sha256, path)
+            download.update(size=size, sha256=sha256)
+        finally:
+            download["ended_at"] = _now()
 
     def _spawn(self, work: Awaitable) -> None:
         task = asyncio.ensure_future(work)
diff --git a/packages/agentenv-protocol/src/agentenv_protocol/website_browser/shapes.py b/packages/agentenv-protocol/src/agentenv_protocol/website_browser/shapes.py
index d4bfc8a1..74b6c675 100644
--- a/packages/agentenv-protocol/src/agentenv_protocol/website_browser/shapes.py
+++ b/packages/agentenv-protocol/src/agentenv_protocol/website_browser/shapes.py
@@ -97,7 +97,7 @@ class ClosedTab(BaseModel):
 
 
 class Download(BaseModel):
-    """A download into ``~/Downloads``; completed, with where it landed, its size and its sha256."""
+    """A download into ``~/Downloads``; when completed, with where it landed, and its size and sha256 when available."""
     guid: str
     url: str
     filename: str
diff --git a/packages/agentenv-protocol/tests/test_website_browser.py b/packages/agentenv-protocol/tests/test_website_browser.py
index 07f906d9..b9294f7c 100644
--- a/packages/agentenv-protocol/tests/test_website_browser.py
+++ b/packages/agentenv-protocol/tests/test_website_browser.py
@@ -909,6 +909,27 @@ async def test_its_control_records_a_completed_download_with_its_size_and_sha256
     assert done["sha256"] == hashlib.sha256(b"%PDF-1.7 report").hexdigest()
 
 
+@pytest.mark.asyncio
+async def test_its_control_records_ended_at_when_download_hashing_fails(tmp_path):
+    devtools = StubDevTools()
+    control = BrowserControl(devtools, "agent")
+    missing_file = tmp_path / "nonexistent.pdf"
+
+    devtools.send("Browser.downloadWillBegin", {"guid": "g2", "url": "https://a.test/missing.pdf",
+                                                "suggestedFilename": "missing.pdf"})
+    devtools.send("Browser.downloadProgress", {"guid": "g2", "state": "completed",
+                                               "filePath": str(missing_file)})
+    for _ in range(int(WAIT_S / POLL_S)):
+        if "ended_at" in control.downloads.get("g2", {}):
+            break
+        await asyncio.sleep(POLL_S)
+
+    done = control.downloads["g2"]
+    assert done["state"] == "completed"
+    assert "ended_at" in done
+    assert "sha256" not in done
+
+
 @pytest.mark.asyncio
 async def test_its_control_says_the_tab_whose_page_has_focus_is_active_else_the_first_visible_one(tmp_path):
     states = {"s-a": ["hidden", False], "s-b": ["visible", False], "s-c": ["visible", True]}