diff --git a/kwant/builder.py b/kwant/builder.py
index 0972b8d2624a1cd03fdcbf46b87340fccf7492d3..fc2408a9067cd97319c4b3c9dfb170e60b1439c2 100644
--- a/kwant/builder.py
+++ b/kwant/builder.py
@@ -124,7 +124,7 @@ class SiteFamily(object):
         except AttributeError:
             return False
 
-    def __neq__(self, other):
+    def __ne__(self, other):
         try:
             return self.canonical_repr != other.canonical_repr
         except AttributeError: