diff --git a/server/app/routers/pages.py b/server/app/routers/pages.py
index 9c6c687..0b183aa 100644
--- a/server/app/routers/pages.py
+++ b/server/app/routers/pages.py
@@ -310,6 +310,23 @@ def _render_claim(request: Request, db: Session, device_id: str, error: str | No
         frame.owner_user_id == user.id or db.get(UserFrame, (user.id, frame.id)) is not None
     ):
         status, pending_yours = "claimed_yours", False
+        if frame.device_token_ack:
+            # The device's captive portal redirects here on EVERY
+            # (re)provisioning cycle (see wifi_provisioning.c) -- if the
+            # physical frame was reset/reprovisioned, it no longer has
+            # the access token this frame row already acknowledged, and
+            # auth.require_device permanently locks out an id-only
+            # request once device_token_ack is set (device_id alone,
+            # unlike the token, isn't secret -- it's shown on the
+            # frame's own screen/QR). Reopening that handshake window
+            # here is what "give it a minute to connect" below actually
+            # depends on: it's safe because landing on this branch
+            # already requires knowing the device_id (physical/local
+            # access to the frame) AND being logged in as an owner/
+            # linked user of it.
+            frame.device_token_ack = False
+            db.commit()
+            logger.info("Frame #%d's device token handshake reopened (re-provisioned)", frame.id)
     else:
         status, pending_yours = "claimed", False
     return templates.TemplateResponse(
diff --git a/server/tests/test_claim_reprovision.py b/server/tests/test_claim_reprovision.py
new file mode 100644
index 0000000..0e740bc
--- /dev/null
+++ b/server/tests/test_claim_reprovision.py
@@ -0,0 +1,82 @@
+"""A physical frame's device_token_ack becomes permanently sticky once
+set (see app/auth.py's require_device) -- if the device is reset/
+reprovisioned, it loses its access token and gets locked out with a 401
+forever unless something reopens that handshake window. The device's
+own captive portal redirects the phone's browser to /claim?device_id=
+on every (re)provisioning cycle (see firmware/main/wifi_provisioning.c),
+so pages.py's _render_claim uses that as the hook to auto-reset the ack
+flag for a logged-in owner/linked user -- see routers/pages.py."""
+
+from __future__ import annotations
+
+from app.models import Frame
+
+from .conftest import link_user, login, make_user
+
+
+def test_claim_page_resets_device_token_ack_for_owner(client, db_session):
+    client.post("/setup", data={"username": "alice", "password": "hunter22"})
+    frame = db_session.get(Frame, 1)
+    frame.device_id = "a0f262865898"
+    frame.device_token_ack = True
+    db_session.commit()
+
+    resp = client.get(f"/claim?device_id={frame.device_id}")
+    assert resp.status_code == 200
+
+    db_session.refresh(frame)
+    assert frame.device_token_ack is False
+
+
+def test_claim_page_resets_device_token_ack_for_linked_user(client, db_session):
+    client.post("/setup", data={"username": "alice", "password": "hunter22"})
+    bob = make_user(db_session, "bob")
+    frame = db_session.get(Frame, 1)
+    link_user(db_session, bob, frame)
+    frame.device_id = "a0f262865898"
+    frame.device_token_ack = True
+    db_session.commit()
+
+    client.cookies.clear()
+    login(client, "bob")
+
+    resp = client.get(f"/claim?device_id={frame.device_id}")
+    assert resp.status_code == 200
+
+    db_session.refresh(frame)
+    assert frame.device_token_ack is False
+
+
+def test_claim_page_leaves_ack_alone_when_already_false(client, db_session):
+    client.post("/setup", data={"username": "alice", "password": "hunter22"})
+    frame = db_session.get(Frame, 1)
+    frame.device_id = "a0f262865898"
+    db_session.commit()
+    assert frame.device_token_ack is False
+
+    resp = client.get(f"/claim?device_id={frame.device_id}")
+    assert resp.status_code == 200
+
+    db_session.refresh(frame)
+    assert frame.device_token_ack is False
+
+
+def test_claim_page_does_not_reset_ack_for_unrelated_user(client, db_session):
+    """A user with no relationship to the frame lands on the "claimed"
+    (not "claimed_yours") branch -- must not be able to reopen another
+    household's device handshake just by knowing its device_id."""
+    client.post("/setup", data={"username": "alice", "password": "hunter22"})
+    frame = db_session.get(Frame, 1)
+    frame.device_id = "a0f262865898"
+    frame.device_token_ack = True
+    db_session.commit()
+
+    make_user(db_session, "mallory")
+    client.cookies.clear()
+    login(client, "mallory")
+
+    resp = client.get(f"/claim?device_id={frame.device_id}")
+    assert resp.status_code == 200
+
+    db_session.refresh(frame)
+    assert frame.device_token_ack is True