1 files changed, 9 insertions, 7 deletions
diff --git a/slixmpp/stanza/error.py b/slixmpp/stanza/error.py
index 83742a5c..76c6b9cc 100644
--- a/slixmpp/stanza/error.py
+++ b/slixmpp/stanza/error.py
@@ -3,7 +3,7 @@
 # This file is part of Slixmpp.
 # See the file LICENSE for copying permission.
 from __future__ import annotations
-from typing import Optional
+from typing import Optional, Dict, Type, ClassVar
 from slixmpp.xmlstream import ElementBase, ET
 
 
@@ -50,10 +50,10 @@ class Error(ElementBase):
     name = 'error'
     plugin_attrib = 'error'
     interfaces = {'code', 'condition', 'text', 'type',
-                      'gone', 'redirect', 'by'}
+                  'gone', 'redirect', 'by'}
     sub_interfaces = {'text'}
-    plugin_attrib_map = {}
-    plugin_tag_map = {}
+    plugin_attrib_map: ClassVar[Dict[str, Type[ElementBase]]] = {}
+    plugin_tag_map: ClassVar[Dict[str, Type[ElementBase]]] = {}
     conditions = {'bad-request', 'conflict', 'feature-not-implemented',
                   'forbidden', 'gone', 'internal-server-error',
                   'item-not-found', 'jid-malformed', 'not-acceptable',
@@ -66,7 +66,7 @@ class Error(ElementBase):
     condition_ns: str = 'urn:ietf:params:xml:ns:xmpp-stanzas'
     types = {'cancel', 'continue', 'modify', 'auth', 'wait'}
 
-    def setup(self, xml: Optional[ET.Element]=None):
+    def setup(self, xml: Optional[ET.Element] = None):
         """
         Populate the stanza object using an optional XML object.
 
@@ -83,7 +83,9 @@ class Error(ElementBase):
             self['type'] = 'cancel'
             self['condition'] = 'feature-not-implemented'
         if self.parent is not None:
-            self.parent()['type'] = 'error'
+            parent = self.parent()
+            if parent:
+                parent['type'] = 'error'
 
     def get_condition(self) -> str:
         """Return the condition element's name."""
@@ -106,7 +108,7 @@ class Error(ElementBase):
             self.xml.append(ET.Element("{%s}%s" % (self.condition_ns, value)))
         return self
 
-    def del_condition(self) -> None:
+    def del_condition(self) -> Error:
         """Remove the condition element."""
         for child in self.xml:
             if "{%s}" % self.condition_ns in child.tag: