diff --git a/SimPEG/Mesh/InnerProducts.py b/SimPEG/Mesh/InnerProducts.py
index 17747f10..7a1a7869 100644
--- a/SimPEG/Mesh/InnerProducts.py
+++ b/SimPEG/Mesh/InnerProducts.py
@@ -383,7 +383,7 @@ def _getFacePx_Rectangular(M):
     """Returns a function for creating projection matrices
 
     """
-    i = np.int64(range(M.nCx))
+    ii = np.int64(range(M.nCx))
 
     def Px(xFace):
         """