diff --git a/src/utils/idmapper/base.py b/src/utils/idmapper/base.py
index d745d21ed7..a421a89f5c 100755
--- a/src/utils/idmapper/base.py
+++ b/src/utils/idmapper/base.py
@@ -292,8 +292,9 @@ class WeakSharedMemoryModelBase(SharedMemoryModelBase):
     Uses a WeakValue dictionary for caching instead of a regular one
     """
     def _prepare(cls):
-        cls.__instance_cache__ = WeakValueDictionary()
         super(WeakSharedMemoryModelBase, cls)._prepare()
+        cls.__instance_cache__ = WeakValueDictionary()
+        cls._idmapper_recache_protection = False
 
 class WeakSharedMemoryModel(SharedMemoryModel):
     """