diff --git a/src/tools/call-omo-agent/sync-executor.test.ts b/src/tools/call-omo-agent/sync-executor.test.ts
index 18f1147f2..aab485706 100644
--- a/src/tools/call-omo-agent/sync-executor.test.ts
+++ b/src/tools/call-omo-agent/sync-executor.test.ts
@@ -395,6 +395,26 @@ describe("executeSync", () => {
     expect(spawnReservation.commit).toHaveBeenCalledTimes(1)
     expect(spawnReservation.rollback).toHaveBeenCalledTimes(0)
   })
+
+  test("strips legacy ZWSP-prefixed agent names from persisted sync prompt body (GH-3259)", async () => {
+    //#given - persisted sync invocation from v3.14.0-v3.16.0 with ZWSP prefix on subagent_type
+    const executeSync = await importExecuteSync()
+    const deps = createDependencies()
+    const toolContext = createToolContext()
+    const recorder = createPromptAsyncRecorder()
+    const args = {
+      subagent_type: "\u200B\u200BHephaestus - Deep Agent",
+      description: "legacy zwsp",
+      prompt: "find something",
+      run_in_background: false,
+    }
+
+    //#when
+    await executeSync(args, toolContext, createContext(recorder.promptAsync) as never, deps)
+
+    //#then
+    expect(recorder.getCapturedInput()?.body.agent).toBe("Hephaestus - Deep Agent")
+  })
 })
 
 export {}