diff --git a/src/scope_equipment/schema.py b/src/scope_equipment/schema.py
index 1bdfd6a..634646a 100644
--- a/src/scope_equipment/schema.py
+++ b/src/scope_equipment/schema.py
@@ -40,7 +40,7 @@ class ScopeEquipmentRead(ScopeEquipmentBase):
 class ScopeEquipmentPagination(Pagination):
     items: List[ScopeEquipmentRead] = []
 
-EquipmentMasterReadRef = ForwardRef("MasterEquipmentRead")
+
 
 
 class MasterEquipmentRead(DefultBase):
@@ -48,9 +48,11 @@ class MasterEquipmentRead(DefultBase):
     location_tag: Optional[str] = Field(None, title="Location Tag")
     name: str
 
+EquipmentMasterTreeRef = ForwardRef("MasterEquipmentTree")
+
 class MasterEquipmentTree(MasterEquipmentRead):
     parent_id: Optional[UUID]
-    parent: Optional[EquipmentMasterReadRef] = Field(None) # type: ignore
+    parent: Optional[EquipmentMasterTreeRef] = Field(None) # type: ignore
 
 class MasterEquipmentPagination(Pagination):
     items: List[MasterEquipmentRead] = []