diff --git a/coding-agent/src/coding_agent/tools/shell.py b/coding-agent/src/coding_agent/tools/shell.py
index 5a2505a4c..b112ef443 100644
--- a/coding-agent/src/coding_agent/tools/shell.py
+++ b/coding-agent/src/coding_agent/tools/shell.py
@@ -233,7 +233,7 @@ def _validated_execution_cwd(
 
 def _validate_no_path_escape(args: list[str], workspace_root: Path) -> None:
     for arg in args[1:]:
-        for match in re.findall(r"/[A-Za-z0-9_./-]+", arg):
+        for match in re.findall(r"(?<![A-Za-z0-9_.-])/[A-Za-z0-9_./-]+", arg):
             candidate = Path(match).expanduser().resolve()
             try:
                 candidate.relative_to(workspace_root)
diff --git a/coding-agent/tests/tools/test_shell.py b/coding-agent/tests/tools/test_shell.py
index 7f803c182..2f65ccdd1 100644
--- a/coding-agent/tests/tools/test_shell.py
+++ b/coding-agent/tests/tools/test_shell.py
@@ -174,6 +174,27 @@ def test_none_sandbox_blocks_absolute_path_escape(self, tmp_path: Path):
         assert str(workspace).lower() in blocked_text
         assert "secret" not in blocked_text
 
+    def test_none_sandbox_allows_relative_paths_with_slashes(self, tmp_path: Path):
+        workspace = tmp_path / "workspace"
+        workspace.mkdir()
+        pipeline_ctx = SimpleNamespace(
+            config={"workspace_root": str(workspace), "shell": {"sandbox_mode": "none"}}
+        )
+
+        mkdir_result = bash_run(
+            command="mkdir -p src/mini_strings tests",
+            cwd=str(workspace),
+            __pipeline_ctx__=pipeline_ctx,
+        )
+        pytest_result = bash_run(
+            command="python3 -m pytest tests/test_slug.py -q",
+            cwd=str(workspace),
+            __pipeline_ctx__=pipeline_ctx,
+        )
+
+        assert _as_text(mkdir_result) == "(no output)"
+        assert "outside sandbox workspace" not in _as_text(pytest_result).lower()
+
     def test_cd_outside_workspace_is_rejected(self, tmp_path: Path):
         workspace = tmp_path / "workspace"
         workspace.mkdir()