diff --git a/prototype/Doubt/Free.swift b/prototype/Doubt/Free.swift
index 2e8a41d90..a2bb266c9 100644
--- a/prototype/Doubt/Free.swift
+++ b/prototype/Doubt/Free.swift
@@ -115,7 +115,7 @@ extension Free {
 	///
 	/// Unfolds a tree bottom-up by recursively applying `transform` to a series of values starting with `seed`. Since `Syntax.Leaf` does not recur, this will halt when it has produced leaves for every branch.
 	public static func ana<Seed>(transform: Seed -> Syntax<Seed, Leaf>)(_ seed: Seed) -> Free {
-		return (Roll <<< { $0.map(ana(transform)) } <<< transform)(seed)
+		return (Roll <<< { $0.map(ana(transform)) } <<< transform) <| seed
 	}
 }