diff --git a/pdbfixer/pdbfixer.py b/pdbfixer/pdbfixer.py
index 645fcdd..5b8046d 100644
--- a/pdbfixer/pdbfixer.py
+++ b/pdbfixer/pdbfixer.py
@@ -1542,7 +1542,7 @@ def addMembrane(self, lipidType='POPC', membraneCenterZ=0*unit.nanometer, minimu
         nChains = sum(1 for _ in self.topology.chains())
         modeller = app.Modeller(self.topology, self.positions)
         forcefield = self._createForceField(self.topology, True)
-        modeller.addMembrane(forcefield, lipidType=lipidType, minimumPadding=minimumPadding, positiveIon=positiveIon, negativeIon=negativeIon, ionicStrength=ionicStrength)
+        modeller.addMembrane(forcefield, lipidType=lipidType, membraneCenterZ=membraneCenterZ, minimumPadding=minimumPadding, positiveIon=positiveIon, negativeIon=negativeIon, ionicStrength=ionicStrength)
         self.topology = modeller.topology
         self.positions = modeller.positions
         self._renameNewChains(nChains)