diff --git a/boxes/__init__.py b/boxes/__init__.py
index 74dc337..72c664b 100755
--- a/boxes/__init__.py
+++ b/boxes/__init__.py
@@ -288,7 +288,7 @@ class Boxes:
             elif arg == "top_edge":
                 self.argparser.add_argument(
                     "--top_edge", action="store",
-                    type=ArgparseEdgeType("ecESik"), choices=list("ecESik"),
+                    type=ArgparseEdgeType("ecESikf"), choices=list("ecESikf"),
                     default="e", help="edge type for top edge")
             elif arg == "outside":
                 self.argparser.add_argument(
diff --git a/boxes/generators/box2.py b/boxes/generators/box2.py
index e1c6ac3..635fe68 100755
--- a/boxes/generators/box2.py
+++ b/boxes/generators/box2.py
@@ -123,6 +123,8 @@ class Box2(Boxes):
 
         if self.top_edge == "c":
             self.rectangularWall(x, y, "CCCC", bedBolts=[d2, d3, d2, d3], move="up")
+        elif self.top_edge == "f":
+            self.rectangularWall(x, y, "FFFF", move="up")
         elif self.top_edge == "i":
             self.rectangularWall(x, y, "IEJe", move="up")
         elif self.top_edge == "k":