diff --git a/agent/shell_hooks.py b/agent/shell_hooks.py
index c1cec81df3332..e2f1fc4265532 100644
--- a/agent/shell_hooks.py
+++ b/agent/shell_hooks.py
@@ -464,7 +464,8 @@ def _spawn(spec: ShellHookSpec, stdin_json: str) -> Dict[str, Any]:
             input=stdin_json,
             capture_output=True,
             timeout=spec.timeout,
-            text=True,
+            encoding='utf-8',
+            errors='replace',
             shell=False,
             **_popen_kwargs,
         )