diff --git a/src/Graph.hs b/src/Graph.hs
index 09a2f7d..891ce4d 100644
--- a/src/Graph.hs
+++ b/src/Graph.hs
@@ -63,9 +63,9 @@ rewind graph = graph {focus = root graph}
 
 follow :: Ord edge => Graph edge label -> edge -> Maybe (Graph edge label)
 follow graph@(Graph {vertices, focus}) edge =
-  Map.lookup edge (edges $ vertices ! focus) >>= \vertexID -> Just $ graph {
-      focus = vertexID
-    }
+  setFocus <$> Map.lookup edge (edges $ vertices ! focus)
+  where
+    setFocus vertexID = graph {focus = vertexID}
 
 stitch :: (Monoid label, Ord edge) => Graph edge label -> edge -> Graph edge label
 stitch graph edge =