diff --git a/boxes/lids.py b/boxes/lids.py
index f97e641..753760d 100644
--- a/boxes/lids.py
+++ b/boxes/lids.py
@@ -115,7 +115,7 @@ class _TopEdge(Boxes):
             t3 = "N"
         elif t1.char == "v":
             t2 = t3 = t4 = "e"
-        if t1.char == "t":
+        elif t1.char == "t":
             t1 = t3 = "e"
         return [t1, t2, t3, t4]