diff --git a/src/Diagram.hs b/src/Diagram.hs
index 0f688cb..375e890 100644
--- a/src/Diagram.hs
+++ b/src/Diagram.hs
@@ -34,11 +34,6 @@ data Diagram vtx = Diagram
   }
   deriving (Show, Read)
 
-data Direction
-  = Up
-  | Down
-  deriving (Eq, Ord, Read, Show)
-
 data InsertError vtx
   = InsertError_DuplicateVertex
   | InsertError_UnknownDownVertex vtx