diff --git a/src/ad_seller/services/approval_service.py b/src/ad_seller/services/approval_service.py
index 47ba171..53f35f2 100644
--- a/src/ad_seller/services/approval_service.py
+++ b/src/ad_seller/services/approval_service.py
@@ -124,9 +124,11 @@ async def _resume_proposal_flow(request, response):
 
     snapshot = request.flow_state_snapshot
 
-    # Re-hydrate state from snapshot
+    # Re-hydrate state from snapshot. CrewAI 1.15 made ``Flow.state`` a
+    # read-only property; assigning it raises AttributeError (HTTP 500).
+    # ``_state`` is the PrivateAttr the property reads.
     flow = ProposalHandlingFlow()
-    flow.state = ProposalState(**snapshot)
+    flow._state = ProposalState(**(snapshot or {}))
 
     # Apply the human decision
     if response.decision == "approve":
diff --git a/tests/unit/test_approval_gates.py b/tests/unit/test_approval_gates.py
index 77a3c57..428e4fb 100644
--- a/tests/unit/test_approval_gates.py
+++ b/tests/unit/test_approval_gates.py
@@ -138,6 +138,49 @@ async def test_unauthenticated_list_and_resume_rejected(self, client, mock_stora
         assert list_resp.status_code == 401
         assert resume_resp.status_code == 401
 
+    async def test_authenticated_resume_after_decide_returns_200(self, client, mock_storage):
+        """Resume after a recorded decision must not 500 on CrewAI's read-only state."""
+        from ad_seller.events.models import ApprovalResponse
+
+        raw_key = _seed_key(mock_storage._store, key_id="key-resume", agency_id="agency-resume")
+        req = ApprovalRequest(
+            event_id="evt-resume",
+            flow_id="flow-resume",
+            flow_type="proposal_handling",
+            gate_name="proposal_decision",
+            proposal_id="prop-resume",
+            status=ApprovalStatus.APPROVED,
+            flow_state_snapshot={
+                "proposal_id": "prop-resume",
+                "flow_id": "flow-resume",
+                "flow_type": "proposal_handling",
+            },
+        )
+        mock_storage._store[f"approval:{req.approval_id}"] = req.model_dump(mode="json")
+        mock_storage._store[f"approval_response:{req.approval_id}"] = ApprovalResponse(
+            approval_id=req.approval_id,
+            decision="approve",
+            decided_by="lab",
+        ).model_dump(mode="json")
+
+        with (
+            patch("ad_seller.storage.factory.get_storage", return_value=mock_storage),
+            patch(
+                "ad_seller.events.helpers.emit_event",
+                new_callable=AsyncMock,
+            ),
+        ):
+            resp = await client.post(
+                f"/approvals/{req.approval_id}/resume",
+                headers={"X-Api-Key": raw_key},
+            )
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["proposal_id"] == "prop-resume"
+        assert body["status"] == "accepted"
+        assert body["resumed_from_approval"] == req.approval_id
+
     async def test_authenticated_decide_records_verified_principal(self, client, mock_storage):
         """A valid key authorizes the decision and the audit record stamps the
         VERIFIED principal, not the arbitrary ``decided_by`` body value."""
diff --git a/tests/unit/test_service_layer.py b/tests/unit/test_service_layer.py
index a61dcad..174f990 100644
--- a/tests/unit/test_service_layer.py
+++ b/tests/unit/test_service_layer.py
@@ -398,6 +398,75 @@ async def test_get_approval_not_found(self, mock_storage):
                 await approval_service.get_approval("apr-missing")
         assert exc.value.status_code == 404
 
+    async def test_resume_after_approve_applies_decision(self, mock_storage):
+        """Happy: resume after approve hydrates snapshot via _state, not flow.state."""
+        from ad_seller.events.models import ApprovalRequest, ApprovalResponse, ApprovalStatus
+
+        req = ApprovalRequest(
+            event_id="evt-1",
+            flow_id="flow-1",
+            flow_type="proposal_handling",
+            gate_name="proposal_decision",
+            proposal_id="prop-1",
+            status=ApprovalStatus.APPROVED,
+            flow_state_snapshot={
+                "proposal_id": "prop-1",
+                "flow_id": "flow-1",
+                "flow_type": "proposal_handling",
+            },
+        )
+        mock_storage._store[f"approval:{req.approval_id}"] = req.model_dump(mode="json")
+        mock_storage._store[f"approval_response:{req.approval_id}"] = ApprovalResponse(
+            approval_id=req.approval_id,
+            decision="approve",
+            decided_by="lab",
+        ).model_dump(mode="json")
+
+        with (
+            patch("ad_seller.storage.factory.get_storage", return_value=mock_storage),
+            patch("ad_seller.events.helpers.emit_event", new_callable=AsyncMock),
+        ):
+            result = await approval_service.resume_flow(req.approval_id)
+
+        assert result["proposal_id"] == "prop-1"
+        assert result["status"] == "accepted"
+        assert result["recommendation"] == "approve"
+        assert result["resumed_from_approval"] == req.approval_id
+
+    async def test_resume_after_reject_applies_decision(self, mock_storage):
+        """Happy: reject path also resumes without assigning the read-only property."""
+        from ad_seller.events.models import ApprovalRequest, ApprovalResponse, ApprovalStatus
+
+        req = ApprovalRequest(
+            event_id="evt-2",
+            flow_id="flow-2",
+            flow_type="proposal_handling",
+            gate_name="proposal_decision",
+            proposal_id="prop-2",
+            status=ApprovalStatus.REJECTED,
+            flow_state_snapshot={
+                "proposal_id": "prop-2",
+                "flow_id": "flow-2",
+                "flow_type": "proposal_handling",
+            },
+        )
+        mock_storage._store[f"approval:{req.approval_id}"] = req.model_dump(mode="json")
+        mock_storage._store[f"approval_response:{req.approval_id}"] = ApprovalResponse(
+            approval_id=req.approval_id,
+            decision="reject",
+            decided_by="lab",
+        ).model_dump(mode="json")
+
+        with (
+            patch("ad_seller.storage.factory.get_storage", return_value=mock_storage),
+            patch("ad_seller.events.helpers.emit_event", new_callable=AsyncMock),
+        ):
+            result = await approval_service.resume_flow(req.approval_id)
+
+        assert result["proposal_id"] == "prop-2"
+        assert result["status"] == "rejected"
+        assert result["recommendation"] == "reject"
+
 
 # =============================================================================
 # session_service