diff --git a/src/Mod/Ship/TankInstance.py b/src/Mod/Ship/TankInstance.py
index 19288ffe8..e35b7f520 100644
--- a/src/Mod/Ship/TankInstance.py
+++ b/src/Mod/Ship/TankInstance.py
@@ -54,7 +54,6 @@ class ShipTank:
             return
         obj.Shape = shape
         obj.Proxy = self
-        self.obj = obj
 
     def onChanged(self, fp, prop):
         """ Property changed, tank must be recomputed """