diff --git a/src/flow/traversible.rs b/src/flow/traversible.rs
index d7c97dc..357e7e2 100644
--- a/src/flow/traversible.rs
+++ b/src/flow/traversible.rs
@@ -15,7 +15,7 @@ pub enum Comparison {
     R,
 }
 
-fn and(_l: (), _r: ()) -> () {}
+fn and(_l: (), _r: ()) {}
 
 /// Returns [`Comparison`] saying which value is smaller.
 ///