diff --git a/pym/portage/package/ebuild/_config/LocationsManager.py b/pym/portage/package/ebuild/_config/LocationsManager.py
index 368c0dd..337edc4 100644
--- a/pym/portage/package/ebuild/_config/LocationsManager.py
+++ b/pym/portage/package/ebuild/_config/LocationsManager.py
@@ -28,6 +28,9 @@
 _profile_node = collections.namedtuple('_profile_node',
 	'location portage1_directories')
 
+_allow_directories = frozenset(
+	["portage-1-compat", "portage-1"])
+
 class LocationsManager(object):
 
 	def __init__(self, config_root=None, eprefix=None, config_profile_path=None, local_config=True, \
@@ -130,7 +133,7 @@
 			# protect against nested repositories.  Insane configuration, but the longest
 			# path will be the correct one.
 			repo_loc, layout_data = max(intersecting_repos, key=lambda x:len(x[0]))
-			allow_directories = any(x.startswith("portage-1")
+			allow_directories = any(x in _allow_directories
 				for x in layout_data['profile-formats'])
 			compat_mode = layout_data['profile-formats'] == ('portage-1-compat',)
 
diff --git a/pym/portage/repository/config.py b/pym/portage/repository/config.py
index 71aefde..872c189 100644
--- a/pym/portage/repository/config.py
+++ b/pym/portage/repository/config.py
@@ -27,6 +27,9 @@
 from portage import _encodings
 from portage import manifest
 
+_valid_profile_formats = frozenset(
+	['pms', 'portage-1'])
+
 _repo_name_sub_re = re.compile(r'[^\w-]')
 
 def _gen_valid_repo(name):
@@ -754,7 +757,7 @@
 			raw_formats = ('portage-1-compat',)
 	else:
 		raw_formats = set(raw_formats.split())
-		unknown = raw_formats.difference(['pms', 'portage-1'])
+		unknown = raw_formats.difference(_valid_profile_formats)
 		if unknown:
 			repo_name = _get_repo_name(repo_location, cached=repo_name)
 			warnings.warn((_("Repository named '%(repo_name)s' has unsupported "
@@ -764,7 +767,7 @@
 				layout_filename=layout_filename,
 				unknown_fmts=" ".join(unknown))),
 				DeprecationWarning)
-		raw_formats = tuple(raw_formats.intersection(['pms', 'portage-1']))
+		raw_formats = tuple(raw_formats.intersection(_valid_profile_formats))
 	data['profile-formats'] = raw_formats
 
 	return data, layout_errors