diff --git a/packages/opencode/test/session/prompt.test.ts b/packages/opencode/test/session/prompt.test.ts
index 5e97e850b..af6ac62c0 100644
--- a/packages/opencode/test/session/prompt.test.ts
+++ b/packages/opencode/test/session/prompt.test.ts
@@ -1677,7 +1677,7 @@ unix(
 
       yield* llm.tool("bash", {
         command:
-          'i=0; while [ "$i" -lt 4000 ]; do printf "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx %05d\\n" "$i"; i=$((i + 1)); done; sleep 30',
+          'i=0; while [ "$i" -lt 4000 ]; do printf "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx %05d\\n" "$i"; i=$((i + 1)); done; printf truncation-ready; sleep 30',
         description: "Print many lines",
         timeout: 30_000,
         workdir: path.resolve(dir),
@@ -1685,7 +1685,15 @@ unix(
 
       const run = yield* prompt.loop({ sessionID: chat.id }).pipe(Effect.forkChild)
       yield* llm.wait(1)
-      yield* Effect.sleep(150)
+      yield* pollWithTimeout(
+        Effect.gen(function* () {
+          const msgs = yield* MessageV2.filterCompactedEffect(chat.id)
+          const assistant = msgs.findLast((item) => item.info.role === "assistant")
+          const tool = assistant ? toolPart(assistant.parts) : undefined
+          if (tool?.state.status === "running" && tool.state.metadata?.output.includes("truncation-ready")) return true
+        }),
+        "timed out waiting for truncated shell output",
+      )
       yield* prompt.cancel(chat.id)
 
       const exit = yield* Fiber.await(run)