diff --git a/src/main/runtime/orca-runtime-tests/terminal-creation-and-readiness-part-08.spec.ts b/src/main/runtime/orca-runtime-tests/terminal-creation-and-readiness-part-08.spec.ts
index f71e58dcc8b..c3f0e02f00c 100644
--- a/src/main/runtime/orca-runtime-tests/terminal-creation-and-readiness-part-08.spec.ts
+++ b/src/main/runtime/orca-runtime-tests/terminal-creation-and-readiness-part-08.spec.ts
@@ -280,29 +280,49 @@ describe('OrcaRuntimeService', () => {
   })
 
   it('yields chunked terminal input through immediates between writes', async () => {
-    const immediate = vi.spyOn(globalThis, 'setImmediate')
+    const writes: string[] = []
+    const bodyWritten = Promise.withResolvers<void>()
+    let turnObserved = false
+    let secondWriteFollowedTurn = false
+    const runtime = new OrcaRuntimeService(store)
+    runtime.setPtyController({
+      spawn: vi.fn().mockResolvedValue({ id: 'pty-bg' }),
+      write: (_ptyId, data) => {
+        writes.push(data)
+        if (writes.length === 1) {
+          setImmediate(() => {
+            turnObserved = true
+          })
+        } else if (writes.length === 2) {
+          secondWriteFollowedTurn = turnObserved
+          bodyWritten.resolve()
+        }
+        return true
+      },
+      kill: () => true,
+      getForegroundProcess: async () => null
+    })
+    const { handle } = await runtime.createTerminal(`path:${TEST_WORKTREE_PATH}`)
+
+    vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'], shouldClearNativeTimers: true })
     try {
-      const writes: string[] = []
-      const runtime = new OrcaRuntimeService(store)
-      runtime.setPtyController({
-        spawn: vi.fn().mockResolvedValue({ id: 'pty-bg' }),
-        write: (_ptyId, data) => {
-          writes.push(data)
-          return true
-        },
-        kill: () => true,
-        getForegroundProcess: async () => null
-      })
-      const { handle } = await runtime.createTerminal(`path:${TEST_WORKTREE_PATH}`)
-
       const text = `${'x'.repeat(TERMINAL_INPUT_CHUNK_MAX_BYTES)}\nline two\nline three`
-      await runtime.sendTerminal(handle, { text, enter: true }, { inputKind: 'driving' })
+      await Promise.all([
+        runtime.sendTerminal(handle, { text, enter: true }, { inputKind: 'driving' }),
+        (async () => {
+          await bodyWritten.promise
+          // Let the write continuation arm the separate Enter timeout.
+          await new Promise<void>((resolve) => setImmediate(resolve))
+          await vi.runAllTimersAsync()
+        })()
+      ])
 
+      expect(secondWriteFollowedTurn).toBe(true)
       expect(writes.at(-1)).toBe('\r')
       expect(writes.slice(0, -1).join('')).toBe(text)
-      expect(immediate).toHaveBeenCalled()
     } finally {
-      immediate.mockRestore()
+      vi.clearAllTimers()
+      vi.useRealTimers()
     }
   })