@@ -252,6 +252,26 @@ def test_import_teamocil_v1x_skips_env_var(
     assert "environment" not in result
 
 
+def test_import_teamocil_v1x_unknown_pane_keys_warns(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A v1.x pane dict with no recognizable keys warns and produces {} (I4)."""
+    workspace = {
+        "name": "v1x",
+        "windows": [{"name": "w", "panes": [{"width": 50}]}],
+    }
+    with caplog.at_level(logging.WARNING, logger="tmuxp.workspace.importers"):
+        result = importers.import_teamocil(workspace)
+    assert result["windows"][0]["panes"][0] == {}
+    warnings = [
+        r
+        for r in caplog.records
+        if r.levelno == logging.WARNING and "no recognizable keys" in r.msg
+    ]
+    assert len(warnings) == 1
+    assert getattr(warnings[0], "tmux_key", None) == "width"
+
+
 def test_import_teamocil_warns_on_v0x_pane_geometry(
     caplog: pytest.LogCaptureFixture,
 ) -> None: