diff options
Diffstat (limited to 'lib/sqlalchemy/orm/mapper.py')
| -rw-r--r-- | lib/sqlalchemy/orm/mapper.py | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py index 914c29b7f..c08d91b57 100644 --- a/lib/sqlalchemy/orm/mapper.py +++ b/lib/sqlalchemy/orm/mapper.py @@ -761,8 +761,9 @@ class Mapper(_InspectionAttr): del self._configure_failed if not self.non_primary and \ + self.class_manager is not None and \ self.class_manager.is_mapped and \ - self.class_manager.mapper is self: + self.class_manager.mapper is self: instrumentation.unregister_class(self.class_) def _configure_pks(self): |