diff --git a/volatility/framework/interfaces/symbols.py b/volatility/framework/interfaces/symbols.py
index 0c367c450..593cefa88 100644
--- a/volatility/framework/interfaces/symbols.py
+++ b/volatility/framework/interfaces/symbols.py
@@ -79,7 +79,7 @@ class BaseSymbolTableInterface(validity.ValidityRoutines):
             table_mapping = {}
         self.table_mapping = self._check_type(table_mapping, dict)
         self._native_types = self._check_type(native_types, NativeTableInterface)
-        self._sort_symbols = []
+        self._sort_symbols = []  # type: typing.List[typing.Tuple[int, str]]
 
     # ## Required Symbol functions
 
diff --git a/volatility/framework/objects/templates.py b/volatility/framework/objects/templates.py
index d702aa193..bf3dc74fd 100644
--- a/volatility/framework/objects/templates.py
+++ b/volatility/framework/objects/templates.py
@@ -90,6 +90,7 @@ class ReferenceTemplate(interfaces.objects.Template):
     size = property(_unresolved)  # type: typing.ClassVar[typing.Any]
     replace_child = _unresolved  # type: typing.ClassVar[typing.Any]
     relative_child_offset = _unresolved  # type: typing.ClassVar[typing.Any]
+    has_member = _unresolved  # type: typing.ClassVar[typing.Any]
 
     def __call__(self,
                  context: interfaces.context.ContextInterface,
diff --git a/volatility/plugins/windows/userassist.py b/volatility/plugins/windows/userassist.py
index 6b340ffb7..979b4fdc5 100644
--- a/volatility/plugins/windows/userassist.py
+++ b/volatility/plugins/windows/userassist.py
@@ -127,6 +127,7 @@ class UserAssist(interfaces_plugins.PluginInterface):
         super().__init__(*args, **kwargs)
         self._userassist_size = 0
         self._userassist_type_name = "_VOL_USERASSIST_TYPES_7"
+        self._reg_table_name = None
         self._win7 = None
 
     @classmethod