diff --git a/packages/app/src/components/settings-general.tsx b/packages/app/src/components/settings-general.tsx
index d9f82129f9..c45a31cf3f 100644
--- a/packages/app/src/components/settings-general.tsx
+++ b/packages/app/src/components/settings-general.tsx
@@ -48,6 +48,8 @@ type ShellOption = {
   acceptable: boolean
 }
 
+const AUTO_SHELL_VALUE = "__opencode_auto_shell__"
+
 // To prevent audio from overlapping/playing very quickly when navigating the settings menus,
 // delay the playback by 100ms during quick selection changes and pause existing sounds.
 const stopDemoSound = () => {
@@ -179,7 +181,8 @@ export const SettingsGeneral: Component = () => {
   const globalSdk = useGlobalSDK()
 
   const [shells] = createResource<ShellOption[]>(() => globalSdk.client.pty.shells().then((res) => res.data || []))
-  const auto = { value: "", label: "Auto (Default)" }
+  const auto = { value: AUTO_SHELL_VALUE, label: "Auto (Default)" }
+  const currentShell = createMemo(() => globalSync.data.config.shell || AUTO_SHELL_VALUE)
 
   const shellOptions = createMemo(() => {
     const list = shells() || []
@@ -293,12 +296,12 @@ export const SettingsGeneral: Component = () => {
           <Select
             data-action="settings-shell"
             options={shellOptions()}
-            current={shellOptions().find((o) => o.value === globalSync.data.config.shell) ?? auto}
+            current={shellOptions().find((o) => o.value === currentShell()) ?? auto}
             value={(o) => o.value}
             label={(o) => o.label}
             onSelect={(option) => {
               if (!option) return
-              globalSync.updateConfig({ shell: option.value })
+              globalSync.updateConfig({ shell: option.value === AUTO_SHELL_VALUE ? "" : option.value })
             }}
             variant="secondary"
             size="small"
diff --git a/packages/opencode/src/shell/shell.ts b/packages/opencode/src/shell/shell.ts
index 4c2d51faec..99178c619c 100644
--- a/packages/opencode/src/shell/shell.ts
+++ b/packages/opencode/src/shell/shell.ts
@@ -90,7 +90,7 @@ function resolve(file: string) {
 function win() {
   return Array.from(
     new Set(
-      [Bun.which("pwsh"), Bun.which("powershell"), gitbash(), process.env.COMSPEC || "cmd.exe"]
+      [which("pwsh"), which("powershell"), gitbash(), process.env.COMSPEC || "cmd.exe"]
         .filter((item): item is string => Boolean(item))
         .map(full),
     ),
@@ -98,10 +98,8 @@ function win() {
 }
 
 async function unix() {
-  const file = Bun.file("/etc/shells")
-  if (await file.exists()) {
-    return Array.from(new Set((await file.text()).split("\n").filter((line) => line.trim() && !line.startsWith("#"))))
-  }
+  const text = await Filesystem.readText("/etc/shells").catch(() => "")
+  if (text) return Array.from(new Set(text.split("\n").filter((line) => line.trim() && !line.startsWith("#"))))
   return ["/bin/bash", "/bin/zsh", "/bin/sh"]
 }
 
diff --git a/packages/opencode/test/shell/shell.test.ts b/packages/opencode/test/shell/shell.test.ts
index 366f14a8c4..b5c7f8b6a7 100644
--- a/packages/opencode/test/shell/shell.test.ts
+++ b/packages/opencode/test/shell/shell.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, test } from "bun:test"
 import path from "path"
 import { Shell } from "../../src/shell/shell"
 import { Filesystem } from "../../src/util"
+import { which } from "../../src/util/which"
 
 const withShell = async (shell: string | undefined, fn: () => void | Promise<void>) => {
   const prev = process.env.SHELL
@@ -77,7 +78,7 @@ describe("shell", () => {
     })
 
     test("resolves bare PowerShell shells", async () => {
-      const shell = Bun.which("pwsh") || Bun.which("powershell")
+      const shell = which("pwsh") || which("powershell")
       if (!shell) return
       await withShell(path.win32.basename(shell), async () => {
         expect(Shell.preferred()).toBe(shell)