diff --git a/ui-tui/src/lib/clipboard.ts b/ui-tui/src/lib/clipboard.ts
index 93472de7d..4a5387ae2 100644
--- a/ui-tui/src/lib/clipboard.ts
+++ b/ui-tui/src/lib/clipboard.ts
@@ -91,10 +91,13 @@ export async function readClipboardText(
   return null
 }
 
-type WriteCmd = { args: readonly string[]; cmd: string } & (
-  | { stdin: true }
-  | { stdin: false; psScript: (b64: string) => string }
-)
+// PowerShell on Windows/WSL decodes piped stdin with the system ANSI code
+// page (e.g. CP936), not UTF-8, so $input-based writes mangle CJK/emoji. We
+// instead base64-encode the UTF-8 bytes and pass them as a -Command argument,
+// decoding with UTF8.GetString — this removes the stdin-encoding variable
+// entirely (also immune to BOM injection on redirect). PowerShell entries set
+// stdin=false; every other backend reads UTF-8 stdin natively.
+type WriteCmd = { args: readonly string[]; cmd: string; stdin: boolean }
 
 function _powershellWriteScript(b64: string): string {
   return `Set-Clipboard -Value ([System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String('${b64}')))`
@@ -109,18 +112,13 @@ function writeClipboardCommands(
   }
 
   if (platform === 'win32') {
-    return [{ cmd: 'powershell', args: ['-NoProfile', '-NonInteractive'], stdin: false, psScript: _powershellWriteScript }]
+    return [{ cmd: 'powershell', args: ['-NoProfile', '-NonInteractive'], stdin: false }]
   }
 
   const attempts: WriteCmd[] = []
 
   if (env.WSL_INTEROP || env.WSL_DISTRO_NAME) {
-    attempts.push({
-      cmd: 'powershell.exe',
-      args: ['-NoProfile', '-NonInteractive'],
-      stdin: false,
-      psScript: _powershellWriteScript
-    })
+    attempts.push({ cmd: 'powershell.exe', args: ['-NoProfile', '-NonInteractive'], stdin: false })
   }
 
   if (env.WAYLAND_DISPLAY) {
@@ -165,7 +163,7 @@ export async function writeClipboardText(
           child.stdin?.end(text)
         } else {
           const b64 = Buffer.from(text, 'utf8').toString('base64')
-          const script = cmdEntry.psScript(b64)
+          const script = _powershellWriteScript(b64)
           const child = start(cmdEntry.cmd, [...cmdEntry.args, '-Command', script], { stdio: ['ignore', 'ignore', 'ignore'], windowsHide: true })
           child.once('error', () => resolve(false))
           child.once('close', (code: number | null) => resolve(code === 0))