diff --git a/src/PAModelpy/MembraneSector.py b/src/PAModelpy/MembraneSector.py
index 9896d73..03fc5d0 100644
--- a/src/PAModelpy/MembraneSector.py
+++ b/src/PAModelpy/MembraneSector.py
@@ -45,7 +45,6 @@ def _add_membrane_constraint(self, model):
 
         self.membrane_proteins = {}
 
-        self.total_occupied_membrane = 0
         coefficients = {
             model.reactions.get_by_id(model.BIOMASS_REACTION).forward_variable: -self.slope
         }
@@ -109,7 +108,6 @@ def _update_membrane_constraint(self, new_max_area:float, model):
         self.max_membrane_area = new_max_area
         self.membrane_proteins = {}
 
-        self.total_occupied_membrane = 0
         coefficients = {
             model.reactions.get_by_id(model.BIOMASS_REACTION).forward_variable: -self.slope
         }