diff --git a/server/src/services/computer-environment-driver.test.ts b/server/src/services/computer-environment-driver.test.ts
index 816c0ce3123..186e2ee72c1 100644
--- a/server/src/services/computer-environment-driver.test.ts
+++ b/server/src/services/computer-environment-driver.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, it, vi } from "vitest";
+import { resolveEnvironmentExecutionTarget, resolveEnvironmentExecutionTransport } from "./environment-execution-target.js";
 import { createComputerEnvironmentDriver } from "./computer-environment-driver.js";
 
 const state = vi.hoisted(() => {
@@ -12,6 +13,13 @@ vi.mock("./environments.js", () => ({ environmentService: () => state }));
 vi.mock("./instance-settings.js", () => ({ instanceSettingsService: () => ({ getExperimental: async () => ({ enableBoatEnvironments: true }) }) }));
 
 describe("computer environment probe ownership", () => {
+  it("does not construct a computer owner for legacy transport serialization", async () => {
+    const input = { db: {} as never, companyId: "company", adapterType: "paperclip_runner",
+      environment: { id: "environment", driver: "computer", config: {} }, leaseMetadata: null };
+    await expect(resolveEnvironmentExecutionTransport(input)).resolves.toBeNull();
+    await expect(resolveEnvironmentExecutionTarget(input)).rejects.toThrow("computer_lease_required");
+  });
+
   it("keeps stable configuration on one session key and fences a changed model", async () => {
     state.admit.mockClear();
     const db = { update: () => ({ set: () => ({ where: async () => undefined }) }) };
diff --git a/server/src/services/environment-execution-target.ts b/server/src/services/environment-execution-target.ts
index b83014756cd..e529b6752a6 100644
--- a/server/src/services/environment-execution-target.ts
+++ b/server/src/services/environment-execution-target.ts
@@ -679,5 +679,8 @@ export async function resolveEnvironmentExecutionTarget(input: {
 export async function resolveEnvironmentExecutionTransport(
   input: Parameters<typeof resolveEnvironmentExecutionTarget>[0],
 ): Promise<Record<string, unknown> | null> {
+  // Computer execution uses a live owner capability, resolved after workspace
+  // realization. It has no legacy serialized transport to resolve at acquire.
+  if (input.environment.driver === "computer") return null;
   return adapterExecutionTargetToRemoteSpec(await resolveEnvironmentExecutionTarget(input)) as Record<string, unknown> | null;
 }