diff --git a/sqlalchemy_continuum/manager.py b/sqlalchemy_continuum/manager.py
index 766780e9..641e9521 100644
--- a/sqlalchemy_continuum/manager.py
+++ b/sqlalchemy_continuum/manager.py
@@ -32,7 +32,7 @@ def wrapper(self, mapper, connection, target):
                         uow = self.unit_of_work(session)
                         break  # The ConnectionFairy is the same, this connection is a clone
                 else:
-                    raise KeyError
+                    raise
         return func(self, uow, target)
     return wrapper
 
@@ -400,7 +400,7 @@ def append_association_operation(self, conn, table_name, params, op):
                         uow = self.unit_of_work(conn.session)
                         break  # The ConnectionFairy is the same, this connection is a clone
                 else:
-                    raise KeyError
+                    raise
         uow.pending_statements.append(stmt)
 
     def track_cloned_connections(self, c, opt):