diff --git a/prototype/doubt-difftool/main.swift b/prototype/doubt-difftool/main.swift
index 78e0552ac..fd9e3313b 100644
--- a/prototype/doubt-difftool/main.swift
+++ b/prototype/doubt-difftool/main.swift
@@ -172,7 +172,7 @@ let parser = parserForType(aSource.type)
 
 let a = try benchmark("parsing source a") { try parser(aSource.contents) }
 let b = try benchmark("parsing source b") { try parser(bSource.contents) }
-let diff = benchmark("diffing") { Interpreter<Term>(equal: Term.equals(annotation: const(true), leaf: ==), comparable: Interpreter<Term>.comparable { $0.extract.categories }, cost: Free.sum(Patch.sum)).run(a, b) }
+let diff = benchmark("diffing") { Interpreter<Term>(equal: Term.equals(annotation: const(true), leaf: ==), comparable: Interpreter<Term>.comparable { $0.extract.categories }, cost: Free.sum(Patch.sum)).run(a, b).flatMap(refineLeafReplacement(aSource.contents, bSource.contents)) }
 switch arguments.output {
 case .Split:
 	let JSON: Doubt.JSON = [