diff --git a/packages/opencode/src/effect/runner.ts b/packages/opencode/src/effect/runner.ts
index 1e7d4c2966..5d7e8778d7 100644
--- a/packages/opencode/src/effect/runner.ts
+++ b/packages/opencode/src/effect/runner.ts
@@ -181,7 +181,7 @@ export const make = <A, E = never>(
         return [
           Effect.gen(function* () {
             yield* Fiber.interrupt(st.run.fiber)
-            yield* Deferred.await(st.run.done).pipe(Effect.exit, Effect.asVoid)
+            yield* Deferred.fail(st.run.done, new Cancelled()).pipe(Effect.asVoid)
             yield* idleIfCurrent()
           }),
           { _tag: "Idle" } as const,
diff --git a/packages/opencode/test/effect/runner.test.ts b/packages/opencode/test/effect/runner.test.ts
index c37cb276b6..3030ca64e0 100644
--- a/packages/opencode/test/effect/runner.test.ts
+++ b/packages/opencode/test/effect/runner.test.ts
@@ -3,6 +3,11 @@ import { Deferred, Effect, Exit, Fiber, Latch, Ref, Scope } from "effect"
 import { Runner } from "@/effect/runner"
 import { it } from "../lib/effect"
 
+const waitForState = <A, E>(runner: Runner.Runner<A, E>, tag: Runner.State<A, E>["_tag"]) =>
+  Effect.gen(function* () {
+    while (runner.state._tag !== tag) yield* Effect.yieldNow
+  }).pipe(Effect.timeout("1 second"))
+
 describe("Runner", () => {
   // --- ensureRunning semantics ---
 
@@ -152,7 +157,7 @@ describe("Runner", () => {
       const s = yield* Scope.Scope
       const runner = Runner.make<string>(s, { onInterrupt: Effect.succeed("fallback") })
       const fiber = yield* runner.ensureRunning(Effect.never.pipe(Effect.as("never"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Running")
 
       yield* runner.cancel
 
@@ -169,9 +174,9 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s, { onInterrupt: Effect.succeed("fallback") })
 
       const a = yield* runner.ensureRunning(Effect.never.pipe(Effect.as("x"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Running")
       const b = yield* runner.ensureRunning(Effect.succeed("y")).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* Effect.yieldNow
 
       yield* runner.cancel
 
@@ -189,7 +194,7 @@ describe("Runner", () => {
       const s = yield* Scope.Scope
       const runner = Runner.make<string>(s)
       const fiber = yield* runner.ensureRunning(Effect.never.pipe(Effect.as("x"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Running")
       yield* runner.cancel
       yield* Fiber.await(fiber)
 
@@ -215,7 +220,7 @@ describe("Runner", () => {
         )
 
         const a = yield* runner.ensureRunning(first).pipe(Effect.exit, Effect.forkChild)
-        yield* Effect.sleep("10 millis")
+        yield* waitForState(runner, "Running")
 
         const stop = yield* runner.cancel.pipe(Effect.forkChild)
         yield* Deferred.await(hit).pipe(Effect.timeout("250 millis"))
@@ -293,7 +298,7 @@ describe("Runner", () => {
       const gate = yield* Deferred.make<void>()
 
       const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("first"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
 
       const exit = yield* runner.startShell(Effect.succeed("second")).pipe(Effect.exit)
       expect(Exit.isFailure(exit)).toBe(true)
@@ -314,7 +319,7 @@ describe("Runner", () => {
       })
 
       const sh = yield* runner.startShell(Effect.never.pipe(Effect.as("aborted"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
 
       const exit = yield* runner.startShell(Effect.succeed("second")).pipe(Effect.exit)
       expect(Exit.isFailure(exit)).toBe(true)
@@ -333,7 +338,7 @@ describe("Runner", () => {
       const gate = yield* Deferred.make<void>()
 
       const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("ignored"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
 
       const stop = yield* runner.cancel.pipe(Effect.forkChild)
       const stopExit = yield* Fiber.await(stop).pipe(Effect.timeout("250 millis"))
@@ -380,11 +385,11 @@ describe("Runner", () => {
       const gate = yield* Deferred.make<void>()
 
       const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("shell-result"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
       expect(runner.state._tag).toBe("Shell")
 
       const run = yield* runner.ensureRunning(Effect.succeed("run-result")).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "ShellThenRun")
       expect(runner.state._tag).toBe("ShellThenRun")
 
       yield* Deferred.succeed(gate, undefined)
@@ -406,7 +411,7 @@ describe("Runner", () => {
       const gate = yield* Deferred.make<void>()
 
       const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("shell"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
 
       const work = Effect.gen(function* () {
         yield* Ref.update(calls, (n) => n + 1)
@@ -414,7 +419,7 @@ describe("Runner", () => {
       })
       const a = yield* runner.ensureRunning(work).pipe(Effect.forkChild)
       const b = yield* runner.ensureRunning(work).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "ShellThenRun")
 
       yield* Deferred.succeed(gate, undefined)
       yield* Fiber.await(sh)
@@ -433,10 +438,10 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s)
 
       const sh = yield* runner.startShell(Effect.never.pipe(Effect.as("aborted"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
 
       const run = yield* runner.ensureRunning(Effect.succeed("y")).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "ShellThenRun")
       expect(runner.state._tag).toBe("ShellThenRun")
 
       yield* runner.cancel
@@ -472,7 +477,7 @@ describe("Runner", () => {
         onIdle: Ref.update(count, (n) => n + 1),
       })
       const fiber = yield* runner.ensureRunning(Effect.never.pipe(Effect.as("x"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Running")
       yield* runner.cancel
       yield* Fiber.await(fiber)
       expect(yield* Ref.get(count)).toBeGreaterThanOrEqual(1)
@@ -502,7 +507,7 @@ describe("Runner", () => {
       const gate = yield* Deferred.make<void>()
 
       const fiber = yield* runner.ensureRunning(Deferred.await(gate).pipe(Effect.as("ok"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Running")
       expect(runner.busy).toBe(true)
 
       yield* Deferred.succeed(gate, undefined)
@@ -519,7 +524,7 @@ describe("Runner", () => {
       const gate = yield* Deferred.make<void>()
 
       const fiber = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("ok"))).pipe(Effect.forkChild)
-      yield* Effect.sleep("10 millis")
+      yield* waitForState(runner, "Shell")
       expect(runner.busy).toBe(true)
 
       yield* Deferred.succeed(gate, undefined)