diff --git a/odoo/api.py b/odoo/api.py
index 6ad93648155..507c7153b7f 100644
--- a/odoo/api.py
+++ b/odoo/api.py
@@ -508,6 +508,7 @@ class Environment(Mapping):
                 return env
 
         # otherwise create environment, and add it in the set
+        assert isinstance(cr, BaseCursor)
         self = object.__new__(cls)
         self.cr, self.uid, self.context, self.su = self.args = (cr, uid, frozendict(context), su)
         self.uid_origin = uid_origin
@@ -1361,3 +1362,4 @@ class Starred:
 # keep those imports here in order to handle cyclic dependencies correctly
 from odoo import SUPERUSER_ID
 from odoo.modules.registry import Registry
+from .sql_db import BaseCursor