diff --git a/src/appier_extras/parts/admin/part.py b/src/appier_extras/parts/admin/part.py
index 9f804c46..2147cff1 100644
--- a/src/appier_extras/parts/admin/part.py
+++ b/src/appier_extras/parts/admin/part.py
@@ -251,8 +251,9 @@ def before_request(self):
 
     def exception_handler(self, error):
         import traceback
+        cls = self.__class__
         lines = traceback.format_exc().splitlines()
-        lines = self._lines(lines)
+        lines = cls._lines(lines)
         lines = lines if self.owner.is_devel() else []
         return self.template(
             "error.html.tpl",
diff --git a/src/appier_extras/parts/opbeat/part.py b/src/appier_extras/parts/opbeat/part.py
index 7c7228d8..159bf706 100644
--- a/src/appier_extras/parts/opbeat/part.py
+++ b/src/appier_extras/parts/opbeat/part.py
@@ -79,6 +79,8 @@ def log_exception(
         is_soft = False,
         strict = False
     ):
+        cls = self.__class__
+
         if not strict and is_soft: return
 
         api = self._get_api()
@@ -91,7 +93,7 @@ def log_exception(
             exception.message or str(exception)
 
         lines = traceback.format_exc().splitlines()
-        lines = self._lines(lines)
+        lines = cls._lines(lines)
 
         payload = dict(
             message = message,