diff --git a/tests-unit/utils/extra_config_test.py b/tests-unit/utils/extra_config_test.py
index 1112320d9..69007d753 100644
--- a/tests-unit/utils/extra_config_test.py
+++ b/tests-unit/utils/extra_config_test.py
@@ -591,3 +591,30 @@ def test_explicit_custom_nodes_key(mock_yaml_load, clear_folder_paths, tmp_path)
     assert os.path.normpath(str(tmp_path / "my_nodes")) in \
         folder_paths.folder_names_and_paths["custom_nodes"][0]
 
+
+@patch("yaml.safe_load")
+def test_nested_models_inherits_block_base(mock_yaml_load, clear_folder_paths, tmp_path):
+    """models: block without its own base_path inherits the outer block's base_path."""
+    config_data = {
+        "comfyui": {
+            "base_path": str(tmp_path),
+            "is_default": True,
+            "models": {
+                "checkpoints": "models/checkpoints/",
+            },
+        }
+    }
+    mock_yaml_load.return_value = config_data
+    folder_paths.folder_names_and_paths["checkpoints"] = ([], set())
+
+    yaml_path = str(tmp_path / "extra_paths.yaml")
+    with open(yaml_path, "w") as f:
+        f.write("")
+
+    load_extra_path_config(yaml_path)
+
+    expected = os.path.normpath(str(tmp_path / "models" / "checkpoints"))
+    paths = folder_paths.folder_names_and_paths["checkpoints"][0]
+    assert expected in paths
+    # is_default inherited: path should be at index 0
+    assert paths[0] == expected
diff --git a/utils/extra_config.py b/utils/extra_config.py
index 8ba1bdc38..d14a40a35 100644
--- a/utils/extra_config.py
+++ b/utils/extra_config.py
@@ -81,10 +81,10 @@ def load_extra_path_config(yaml_path: str, allow_system_dirs: bool = False) -> N
                 # New nested style: models: { base_path, is_default, <categories> }
                 has_models_block = True
                 models_conf = dict(value)
-                models_base = None
+                models_base = block_base
                 if "base_path" in models_conf:
                     models_base = _resolve_base(models_conf.pop("base_path"), block_base, yaml_dir)
-                models_is_default = bool(models_conf.pop("is_default", False))
+                models_is_default = bool(models_conf.pop("is_default", block_is_default))
                 explicit: set[str] = set(models_conf.keys())
                 for cat, raw in models_conf.items():
                     _add_model_paths(cat, raw, models_base, yaml_dir, models_is_default)