diff --git a/frontend/src/composables/useTerminal.ts b/frontend/src/composables/useTerminal.ts
index 2d3407b..2cc499e 100644
--- a/frontend/src/composables/useTerminal.ts
+++ b/frontend/src/composables/useTerminal.ts
@@ -114,8 +114,14 @@ export function useTerminal(sessionId: string): UseTerminalReturn {
       }
 
       try {
-        const decoded = atob(b64data);
-        terminal.write(decoded);
+        // atob() returns Latin-1 — each byte becomes a char code 0x00–0xFF.
+        // We must reconstruct the raw bytes, then decode as UTF-8.
+        const binaryStr = atob(b64data);
+        const bytes = new Uint8Array(binaryStr.length);
+        for (let i = 0; i < binaryStr.length; i++) {
+          bytes[i] = binaryStr.charCodeAt(i);
+        }
+        terminal.write(new TextDecoder().decode(bytes));
       } catch {
         // Fallback: write raw if not valid base64
         terminal.write(b64data);