diff --git a/intake_thredds/source.py b/intake_thredds/source.py
index 6370280..1ed3193 100644
--- a/intake_thredds/source.py
+++ b/intake_thredds/source.py
@@ -16,7 +16,7 @@ class THREDDSMergedSource(DataSourceMixin):
     ----------
     url : str
         Location of server
-    path : list of str
+    path : str, list of str
         Subcats to follow; include glob characters (*, ?) in here for matching.
     driver : str
         Select driver to access data. Choose from 'netcdf' and 'opendap'.
@@ -69,6 +69,12 @@ def __init__(
         self.urlpath = url
         if 'simplecache::' in url:
             self.metadata.update({'fsspec_pre_url': 'simplecache::'})
+        if isinstance(path, str):
+            path = [path]
+        if not isinstance(path, list):
+            raise ValueError(f'path must be list of str, found {type(path)}')
+        if not all(isinstance(item, str) for item in path):
+            raise ValueError('path must be list of str')
         self.path = path
         self.driver = driver
         self.xarray_kwargs = xarray_kwargs
diff --git a/tests/test_source.py b/tests/test_source.py
index 473cc6d..1659023 100644
--- a/tests/test_source.py
+++ b/tests/test_source.py
@@ -42,6 +42,18 @@ def THREDDSMergedSource_cat_short(
     return cat
 
 
+@pytest.mark.parametrize('path', [1, [1, 'air.sig995.194*.nc']])
+def test_THREDDSMergedSource_path_error(THREDDSMergedSource_cat_short_url, path):
+    with pytest.raises(ValueError):
+        intake.open_thredds_merged(THREDDSMergedSource_cat_short_url, path)
+
+
+@pytest.mark.parametrize('path', ['air.sig995.194*.nc', ['air.sig995.194*.nc']])
+def test_THREDDSMergedSource_path(THREDDSMergedSource_cat_short_url, path):
+    """THREDDSMergedSource for various types of path."""
+    assert intake.open_thredds_merged(THREDDSMergedSource_cat_short_url, path)
+
+
 @pytest.fixture(scope='module')
 def THREDDSMergedSource_cat_short_simplecache(
     THREDDSMergedSource_cat_short_url, THREDDSMergedSource_cat_short_path