diff --git a/parallel.py b/parallel.py
index a80ff39..5da4329 100644
--- a/parallel.py
+++ b/parallel.py
@@ -497,11 +497,11 @@ class PPP:
         import numpy as np
         self.symmetries[key] = np.zeros((3,3,3),dtype='i')
         for axis in range(3):
-            self.impose_mirror_symmetry(key,axis,-1)
-            self.impose_mirror_symmetry(key,axis,+1)
+            self.init_mirror_symmetry(key,axis,-1)
+            self.init_mirror_symmetry(key,axis,+1)
         return
 
-    def impose_mirror_symmetry(self,key,axis,wall):
+    def init_mirror_symmetry(self,key,axis,wall):
         '''Applies symmetry: [u,v,w](x,-y,z) -> [u,-v,w](x,y,z)
            Proposed by Lozano-Duran JFM 2016 and used for free-slip.'''
         if self.periodicity[axis]: 
@@ -540,6 +540,7 @@ class PPP:
                 self.symmetries[key][sl] = 1
             else:
                 self.symmetries[key][sl] = -1
+            self.impose_boundary_conditions(key)
         return
 
     def copy(self,key,key_out,skip_data=False,skip_symmetries=False):