diff --git a/aeolis/utils.py b/aeolis/utils.py
index 9001abfb..cc7d7c2b 100644
--- a/aeolis/utils.py
+++ b/aeolis/utils.py
@@ -526,10 +526,10 @@ def sweep(Ct, Cu, mass, dt, Ts, ds, dn, us, un, w):
     # ufn[:,:,:] = ufn[-2,:,:]
 
     # also correct for the potential gradients at the boundary cells in the equilibrium concentrations
-    Cu[:,0,:]  = Cu[:,1,:]
-    Cu[:,-1,:] = Cu[:,-2,:]
-    Cu[0,:,:]  = Cu[1,:,:]
-    Cu[-1,:,:] = Cu[-2,:,:]
+    # Cu[:,0,:]  = Cu[:,1,:]
+    # Cu[:,-1,:] = Cu[:,-2,:]
+    # Cu[0,:,:]  = Cu[1,:,:]
+    # Cu[-1,:,:] = Cu[-2,:,:]
     
     # #boundary values
     # ufs[:,0, :]  = us[:,0, :]