diff --git a/server/src/services/heartbeat/workspace-preparation.test.ts b/server/src/services/heartbeat/workspace-preparation.test.ts
index 16fc8fd685d..f0d5d898ce6 100644
--- a/server/src/services/heartbeat/workspace-preparation.test.ts
+++ b/server/src/services/heartbeat/workspace-preparation.test.ts
@@ -1762,12 +1762,16 @@ describe.skipIf(!support.supported && !externalDatabaseUrl)("heartbeat workspace
     }
     const reserve = vi.spyOn(input.services.executionWorkspacesSvc, "assertTaskRepositoryRecoveryBinding");
     const prepare = vi.spyOn(input.services.executionWorkspacesSvc, "prepareTaskRepositoriesForAdmission");
-    if (transport !== "daytona" || descriptor === "valid") {
+    if (descriptor !== "corrupt") {
       const result = await prepareHeartbeatWorkspace(db, input);
       expect(result.executionTarget).toEqual(target);
       if (transport === "ssh" || transport === "task") expect(reserve).not.toHaveBeenCalled();
       else expect(reserve).toHaveBeenCalledWith({ companyId: issue.companyId, issueId: issue.id,
-        workspaceId: first.persistedExecutionWorkspace!.id, cwd: admittedRoot, agentId: input.agent.id, runId: input.run.id });
+        workspaceId: first.persistedExecutionWorkspace!.id,
+        // Without a committed sync descriptor the sandbox never received this
+        // run's work, so recovery re-admits the host workspace it will seed from.
+        cwd: transport === "daytona" && descriptor === "absent" ? first.executionWorkspace.cwd : admittedRoot,
+        agentId: input.agent.id, runId: input.run.id });
       if (transport !== "daytona") {
         await expect(prepareNativeWorkspaceSync({ db, runId: input.run.id, companyId: issue.companyId,
           workspaceId: first.persistedExecutionWorkspace!.id, workspaceLocalDir: first.executionWorkspace.cwd,
@@ -1775,8 +1779,7 @@ describe.skipIf(!support.supported && !externalDatabaseUrl)("heartbeat workspace
       }
       expect(admittedRoot).not.toBe(first.executionWorkspace.cwd);
     } else {
-      await expect(prepareHeartbeatWorkspace(db, input)).rejects.toThrow(descriptor === "absent"
-        ? "native_workspace_sync_descriptor_binding_missing" : "native_workspace_sync_descriptor_digest_mismatch");
+      await expect(prepareHeartbeatWorkspace(db, input)).rejects.toThrow("native_workspace_sync_descriptor_digest_mismatch");
       expect(reserve).not.toHaveBeenCalled();
       expect(await leases(input.run.id)).toMatchObject([{ status: "active" }]);
     }
diff --git a/server/src/services/heartbeat/workspace-preparation.ts b/server/src/services/heartbeat/workspace-preparation.ts
index 239a05ebceb..5f3bc76406c 100644
--- a/server/src/services/heartbeat/workspace-preparation.ts
+++ b/server/src/services/heartbeat/workspace-preparation.ts
@@ -1447,10 +1447,13 @@ async function prepareHeartbeatWorkspaceLocked(db: Db, input: HeartbeatWorkspace
       && !(executionTarget?.kind === "remote" && (executionTarget.transport === "ssh"
         || (executionTarget.transport === "sandbox" && executionTarget.runnerTask)))) {
     const workspaceId = persistedNativeExecutionInput?.binding.executionWorkspaceId ?? nativeRecoveryExecutionWorkspaceId!;
+    // Runtime selection persists the native input before it prepares the
+    // sandbox sync, and commits this reference before any provider dispatch.
+    // An absent reference therefore means preparation was interrupted (for
+    // example by a server restart) before the sandbox received this run's work.
+    // There is no remote copy-back to protect, so recovery re-admits the host
+    // workspace that the fresh sync preparation will seed from.
     const reference = readNativeWorkspaceSyncReference(parseObject(run.runnerProfileJson).nativeWorkspaceSync);
-    if (!reference && executionTarget?.kind === "remote" && executionTarget.transport === "sandbox") {
-      throw new Error("native_workspace_sync_descriptor_binding_missing");
-    }
     const cwd = reference
       ? await readNativeWorkspaceSyncLocalCwd({ companyId: agent.companyId, runId: run.id, workspaceId, reference })
       : nativeExecutionUsesTaskWorkspace(persistedNativeExecutionInput)