diff --git a/packages/opencode/src/effect/runner.ts b/packages/opencode/src/effect/runner.ts
index cb12b4c52b..38c45a6342 100644
--- a/packages/opencode/src/effect/runner.ts
+++ b/packages/opencode/src/effect/runner.ts
@@ -1,10 +1,10 @@
-import { Cause, Deferred, Effect, Exit, Fiber, Option, Schema, Scope, SynchronizedRef } from "effect"
+import { Cause, Deferred, Effect, Exit, Fiber, Schema, Scope, SynchronizedRef } from "effect"
 
 export interface Runner<A, E = never> {
   readonly state: Runner.State<A, E>
   readonly busy: boolean
   readonly ensureRunning: (work: Effect.Effect<A, E>) => Effect.Effect<A, E>
-  readonly startShell: (work: (signal: AbortSignal) => Effect.Effect<A, E>) => Effect.Effect<A, E>
+  readonly startShell: (work: Effect.Effect<A, E>) => Effect.Effect<A, E>
   readonly cancel: Effect.Effect<void>
 }
 
@@ -20,7 +20,6 @@ export namespace Runner {
   interface ShellHandle<A, E> {
     id: number
     fiber: Fiber.Fiber<A, E>
-    abort: AbortController
   }
 
   interface PendingHandle<A, E> {
@@ -100,13 +99,7 @@ export namespace Runner {
         }),
       ).pipe(Effect.flatten)
 
-    const stopShell = (shell: ShellHandle<A, E>) =>
-      Effect.gen(function* () {
-        shell.abort.abort()
-        const exit = yield* Fiber.await(shell.fiber).pipe(Effect.timeoutOption("100 millis"))
-        if (Option.isNone(exit)) yield* Fiber.interrupt(shell.fiber)
-        yield* Fiber.await(shell.fiber).pipe(Effect.exit, Effect.asVoid)
-      })
+    const stopShell = (shell: ShellHandle<A, E>) => Fiber.interrupt(shell.fiber)
 
     const ensureRunning = (work: Effect.Effect<A, E>) =>
       SynchronizedRef.modifyEffect(
@@ -138,7 +131,7 @@ export namespace Runner {
         ),
       )
 
-    const startShell = (work: (signal: AbortSignal) => Effect.Effect<A, E>) =>
+    const startShell = (work: Effect.Effect<A, E>) =>
       SynchronizedRef.modifyEffect(
         ref,
         Effect.fnUntraced(function* (st) {
@@ -153,9 +146,8 @@ export namespace Runner {
           }
           yield* busy
           const id = next()
-          const abort = new AbortController()
-          const fiber = yield* work(abort.signal).pipe(Effect.ensuring(finishShell(id)), Effect.forkChild)
-          const shell = { id, fiber, abort } satisfies ShellHandle<A, E>
+          const fiber = yield* work.pipe(Effect.ensuring(finishShell(id)), Effect.forkChild)
+          const shell = { id, fiber } satisfies ShellHandle<A, E>
           return [
             Effect.gen(function* () {
               const exit = yield* Fiber.await(fiber)
diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index dc75efcdc9..19f0850ff4 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -743,7 +743,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         } satisfies MessageV2.TextPart)
       })
 
-      const shellImpl = Effect.fn("SessionPrompt.shellImpl")(function* (input: ShellInput, signal: AbortSignal) {
+      const shellImpl = Effect.fn("SessionPrompt.shellImpl")(function* (input: ShellInput) {
         const ctx = yield* InstanceState.context
         const session = yield* sessions.get(input.sessionID)
         if (session.revert) {
@@ -1577,7 +1577,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         function* (input: ShellInput) {
           const s = yield* InstanceState.get(state)
           const runner = getRunner(s.runners, input.sessionID)
-          return yield* runner.startShell((signal) => shellImpl(input, signal))
+          return yield* runner.startShell(shellImpl(input))
         },
       )
 
diff --git a/packages/opencode/test/effect/runner.test.ts b/packages/opencode/test/effect/runner.test.ts
index 9dc395876e..a91df76ebf 100644
--- a/packages/opencode/test/effect/runner.test.ts
+++ b/packages/opencode/test/effect/runner.test.ts
@@ -250,7 +250,7 @@ describe("Runner", () => {
     Effect.gen(function* () {
       const s = yield* Scope.Scope
       const runner = Runner.make<string>(s)
-      const result = yield* runner.startShell((_signal) => Effect.succeed("shell-done"))
+      const result = yield* runner.startShell(Effect.succeed("shell-done"))
       expect(result).toBe("shell-done")
       expect(runner.busy).toBe(false)
     }),
@@ -264,7 +264,7 @@ describe("Runner", () => {
       const fiber = yield* runner.ensureRunning(Effect.never.pipe(Effect.as("x"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
 
-      const exit = yield* runner.startShell((_s) => Effect.succeed("nope")).pipe(Effect.exit)
+      const exit = yield* runner.startShell(Effect.succeed("nope")).pipe(Effect.exit)
       expect(Exit.isFailure(exit)).toBe(true)
 
       yield* runner.cancel
@@ -279,12 +279,10 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s)
       const gate = yield* Deferred.make<void>()
 
-      const sh = yield* runner
-        .startShell((_signal) => Deferred.await(gate).pipe(Effect.as("first")))
-        .pipe(Effect.forkChild)
+      const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("first"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
 
-      const exit = yield* runner.startShell((_s) => Effect.succeed("second")).pipe(Effect.exit)
+      const exit = yield* runner.startShell(Effect.succeed("second")).pipe(Effect.exit)
       expect(Exit.isFailure(exit)).toBe(true)
 
       yield* Deferred.succeed(gate, undefined)
@@ -302,37 +300,26 @@ describe("Runner", () => {
         },
       })
 
-      const sh = yield* runner
-        .startShell((signal) =>
-          Effect.promise(
-            () =>
-              new Promise<string>((resolve) => {
-                signal.addEventListener("abort", () => resolve("aborted"), { once: true })
-              }),
-          ),
-        )
-        .pipe(Effect.forkChild)
+      const sh = yield* runner.startShell(Effect.never.pipe(Effect.as("aborted"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
 
-      const exit = yield* runner.startShell((_s) => Effect.succeed("second")).pipe(Effect.exit)
+      const exit = yield* runner.startShell(Effect.succeed("second")).pipe(Effect.exit)
       expect(Exit.isFailure(exit)).toBe(true)
 
       yield* runner.cancel
       const done = yield* Fiber.await(sh)
-      expect(Exit.isSuccess(done)).toBe(true)
+      expect(Exit.isFailure(done)).toBe(true)
     }),
   )
 
   it.live(
-    "cancel interrupts shell that ignores abort signal",
+    "cancel interrupts shell",
     Effect.gen(function* () {
       const s = yield* Scope.Scope
       const runner = Runner.make<string>(s)
       const gate = yield* Deferred.make<void>()
 
-      const sh = yield* runner
-        .startShell((_signal) => Deferred.await(gate).pipe(Effect.as("ignored")))
-        .pipe(Effect.forkChild)
+      const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("ignored"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
 
       const stop = yield* runner.cancel.pipe(Effect.forkChild)
@@ -356,9 +343,7 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s)
       const gate = yield* Deferred.make<void>()
 
-      const sh = yield* runner
-        .startShell((_signal) => Deferred.await(gate).pipe(Effect.as("shell-result")))
-        .pipe(Effect.forkChild)
+      const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("shell-result"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
       expect(runner.state._tag).toBe("Shell")
 
@@ -384,9 +369,7 @@ describe("Runner", () => {
       const calls = yield* Ref.make(0)
       const gate = yield* Deferred.make<void>()
 
-      const sh = yield* runner
-        .startShell((_signal) => Deferred.await(gate).pipe(Effect.as("shell")))
-        .pipe(Effect.forkChild)
+      const sh = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("shell"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
 
       const work = Effect.gen(function* () {
@@ -414,16 +397,7 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s)
       const gate = yield* Deferred.make<void>()
 
-      const sh = yield* runner
-        .startShell((signal) =>
-          Effect.promise(
-            () =>
-              new Promise<string>((resolve) => {
-                signal.addEventListener("abort", () => resolve("aborted"), { once: true })
-              }),
-          ),
-        )
-        .pipe(Effect.forkChild)
+      const sh = yield* runner.startShell(Effect.never.pipe(Effect.as("aborted"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
 
       const run = yield* runner.ensureRunning(Effect.succeed("y")).pipe(Effect.forkChild)
@@ -478,7 +452,7 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s, {
         onBusy: Ref.update(count, (n) => n + 1),
       })
-      yield* runner.startShell((_signal) => Effect.succeed("done"))
+      yield* runner.startShell(Effect.succeed("done"))
       expect(yield* Ref.get(count)).toBe(1)
     }),
   )
@@ -509,9 +483,7 @@ describe("Runner", () => {
       const runner = Runner.make<string>(s)
       const gate = yield* Deferred.make<void>()
 
-      const fiber = yield* runner
-        .startShell((_signal) => Deferred.await(gate).pipe(Effect.as("ok")))
-        .pipe(Effect.forkChild)
+      const fiber = yield* runner.startShell(Deferred.await(gate).pipe(Effect.as("ok"))).pipe(Effect.forkChild)
       yield* Effect.sleep("10 millis")
       expect(runner.busy).toBe(true)