diff --git a/packages/opencode/src/kilocode/shell/shell.ts b/packages/opencode/src/kilocode/shell/shell.ts
new file mode 100644
index 00000000000..34db598e530
--- /dev/null
+++ b/packages/opencode/src/kilocode/shell/shell.ts
@@ -0,0 +1,16 @@
+import { Buffer } from "node:buffer"
+
+export function args(command: string) {
+  return ["-NoLogo", "-NoProfile", "-NonInteractive", "-EncodedCommand", encoded(command)]
+}
+
+function encoded(command: string) {
+  const payload = Buffer.from(command, "utf8").toString("base64")
+  return Buffer.from(
+    `[Console]::InputEncoding = [System.Text.UTF8Encoding]::new($false);
+[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new($false);
+$OutputEncoding = [Console]::OutputEncoding;
+& ([scriptblock]::Create([System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String('${payload}'))))`,
+    "utf16le",
+  ).toString("base64")
+}
diff --git a/packages/opencode/src/shell/shell.ts b/packages/opencode/src/shell/shell.ts
index d86811cba0d..c51a0426efe 100644
--- a/packages/opencode/src/shell/shell.ts
+++ b/packages/opencode/src/shell/shell.ts
@@ -1,4 +1,5 @@
 import { Flag } from "@opencode-ai/core/flag/flag"
+import * as PowerShell from "@/kilocode/shell/shell" // kilocode_change - encoded PowerShell args
 import { lazy } from "@/util/lazy"
 import { Filesystem } from "@/util/filesystem"
 import { which } from "@/util/which"
@@ -169,7 +170,7 @@ export function args(file: string, command: string, cwd: string) {
         cd -- "$1"
         eval ${JSON.stringify(command)}
       `,
-      "opencode",
+      "kilo", // kilocode_change
       cwd,
     ]
   }
@@ -183,12 +184,12 @@ export function args(file: string, command: string, cwd: string) {
         cd -- "$1"
         eval ${JSON.stringify(command)}
       `,
-      "opencode",
+      "kilo", // kilocode_change
       cwd,
     ]
   }
   if (n === "cmd") return ["/c", command]
-  if (ps(file)) return ["-NoProfile", "-Command", command]
+  if (ps(file)) return PowerShell.args(command) // kilocode_change - encoded PowerShell args
   return ["-c", command]
 }
 
diff --git a/packages/opencode/src/tool/shell.ts b/packages/opencode/src/tool/shell.ts
index db3699af116..2261619cb65 100644
--- a/packages/opencode/src/tool/shell.ts
+++ b/packages/opencode/src/tool/shell.ts
@@ -312,7 +312,7 @@ const ask = Effect.fn("ShellTool.ask")(function* (
 
 function cmd(shell: string, command: string, cwd: string, env: NodeJS.ProcessEnv) {
   if (process.platform === "win32" && Shell.ps(shell)) {
-    return ChildProcess.make(shell, ["-NoLogo", "-NoProfile", "-NonInteractive", "-Command", command], {
+    return ChildProcess.make(shell, Shell.args(shell, command, cwd), { // kilocode_change - encoded PowerShell args
       cwd,
       env,
       stdin: "ignore",
diff --git a/packages/opencode/test/kilocode/shell/shell.test.ts b/packages/opencode/test/kilocode/shell/shell.test.ts
new file mode 100644
index 00000000000..99eac3ecb02
--- /dev/null
+++ b/packages/opencode/test/kilocode/shell/shell.test.ts
@@ -0,0 +1,31 @@
+import { describe, expect, test } from "bun:test"
+import { Buffer } from "node:buffer"
+import * as PowerShell from "@/kilocode/shell/shell"
+import { Shell } from "@/shell/shell"
+
+const command = `Write-Output "こんにちは 😀"; Write-Output '$value'; Write-Output \`tick\`
+Write-Output "done"`
+
+function script(args: string[]) {
+  return Buffer.from(args[4], "base64").toString("utf16le")
+}
+
+describe("PowerShell arguments", () => {
+  test("transports commands through UTF-8 inside EncodedCommand", () => {
+    const args = PowerShell.args(command)
+    const value = script(args)
+    const payload = value.match(/FromBase64String\('([^']+)'\)/)?.[1]
+
+    expect(args.slice(0, 4)).toEqual(["-NoLogo", "-NoProfile", "-NonInteractive", "-EncodedCommand"])
+    expect(args).toHaveLength(5)
+    expect(value).toContain("[Console]::InputEncoding = [System.Text.UTF8Encoding]::new($false)")
+    expect(value).toContain("[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new($false)")
+    expect(value).toContain("$OutputEncoding = [Console]::OutputEncoding")
+    expect(payload).toBeDefined()
+    expect(Buffer.from(payload!, "base64").toString("utf8")).toBe(command)
+  })
+
+  test.each(["powershell", "pwsh"])("routes %s through the Kilo argument builder", (shell) => {
+    expect(Shell.args(shell, command, "/tmp")).toEqual(PowerShell.args(command))
+  })
+})