diff --git a/agents/s02_tool_use.py b/agents/s02_tool_use.py
index 8e434c04a..deff34143 100644
--- a/agents/s02_tool_use.py
+++ b/agents/s02_tool_use.py
@@ -51,7 +51,8 @@ def run_bash(command: str) -> str:
         return "Error: Dangerous command blocked"
     try:
         r = subprocess.run(command, shell=True, cwd=WORKDIR,
-                           capture_output=True, text=True, timeout=120)
+                           capture_output=True, text=True,
+                           encoding="utf-8", errors="replace", timeout=120)
         out = (r.stdout + r.stderr).strip()
         return out[:50000] if out else "(no output)"
     except subprocess.TimeoutExpired:
diff --git a/s02_tool_use/code.py b/s02_tool_use/code.py
index 4630521ee..e6575119a 100644
--- a/s02_tool_use/code.py
+++ b/s02_tool_use/code.py
@@ -49,7 +49,8 @@ def run_bash(command: str) -> str:
         return "Error: Dangerous command blocked"
     try:
         r = subprocess.run(command, shell=True, cwd=WORKDIR,
-                           capture_output=True, text=True, timeout=120)
+                           capture_output=True, text=True,
+                           encoding="utf-8", errors="replace", timeout=120)
         out = (r.stdout + r.stderr).strip()
         return out[:50000] if out else "(no output)"
     except subprocess.TimeoutExpired: