diff --git a/pyEDAA/ProjectModel/__init__.py b/pyEDAA/ProjectModel/__init__.py
index f167e2a1..0ad7c7ad 100644
--- a/pyEDAA/ProjectModel/__init__.py
+++ b/pyEDAA/ProjectModel/__init__.py
@@ -643,6 +643,7 @@ class FileSet(metaclass=ExtendedType, slots=True):
 	_parent:          Nullable['FileSet']
 	_fileSets:        Dict[str, 'FileSet']
 	_files:           List[File]
+	_set:             Set
 	_attributes:      Dict[Type[Attribute], typing_Any]
 	_vhdlLibraries:   Dict[str, 'VHDLLibrary']
 	_vhdlLibrary:     'VHDLLibrary'