diff --git a/tests/agent/conftest.py b/tests/agent/conftest.py
index c239733b..9bb4b65b 100644
--- a/tests/agent/conftest.py
+++ b/tests/agent/conftest.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import os
 from pathlib import Path
 from types import SimpleNamespace
 from unittest.mock import AsyncMock, MagicMock, patch
@@ -13,6 +14,12 @@ from nanobot.bus.queue import MessageBus
 from nanobot.providers.base import LLMProvider
 
 
+@pytest.fixture
+def cmd_python() -> str:
+    """Return the Python command name available to ExecTool tests."""
+    return "python" if os.name == "nt" else "python3"
+
+
 def make_provider(
     default_model: str = "test-model",
     *,
diff --git a/tests/agent/test_workspace_scope.py b/tests/agent/test_workspace_scope.py
index 2c5aefa9..8ca76696 100644
--- a/tests/agent/test_workspace_scope.py
+++ b/tests/agent/test_workspace_scope.py
@@ -257,7 +257,10 @@ async def test_filesystem_write_tool_full_scope_allows_outside_project(tmp_path:
 
 
 @pytest.mark.asyncio
-async def test_exec_tool_uses_scope_project_as_default_cwd(tmp_path: Path) -> None:
+async def test_exec_tool_uses_scope_project_as_default_cwd(
+    tmp_path: Path,
+    cmd_python: str,
+) -> None:
     project = tmp_path / "project"
     project.mkdir()
     tool = ExecTool(working_dir=str(tmp_path), restrict_to_workspace=False, timeout=5)
@@ -270,7 +273,7 @@ async def test_exec_tool_uses_scope_project_as_default_cwd(tmp_path: Path) -> No
     try:
         result = await tool.execute(
             command=(
-                'python -c "from pathlib import Path; '
+                f'{cmd_python} -c "from pathlib import Path; '
                 "Path('scoped-marker.txt').write_text('ok')\""
             )
         )
@@ -282,7 +285,10 @@ async def test_exec_tool_uses_scope_project_as_default_cwd(tmp_path: Path) -> No
 
 
 @pytest.mark.asyncio
-async def test_exec_full_scope_allows_explicit_cwd_outside_project(tmp_path: Path) -> None:
+async def test_exec_full_scope_allows_explicit_cwd_outside_project(
+    tmp_path: Path,
+    cmd_python: str,
+) -> None:
     project = tmp_path / "project"
     outside = tmp_path / "outside"
     project.mkdir()
@@ -297,7 +303,7 @@ async def test_exec_full_scope_allows_explicit_cwd_outside_project(tmp_path: Pat
     try:
         result = await tool.execute(
             command=(
-                'python -c "from pathlib import Path; '
+                f'{cmd_python} -c "from pathlib import Path; '
                 "Path('outside-marker.txt').write_text('ok')\""
             ),
             working_dir=str(outside),