diff --git a/prototype/Doubt/Prism.swift b/prototype/Doubt/Prism.swift
index 6d55468ec..9e5fefe57 100644
--- a/prototype/Doubt/Prism.swift
+++ b/prototype/Doubt/Prism.swift
@@ -1,6 +1,6 @@
 public struct Prism<From, To> {
-	let forward: From -> To?
-	let backward: To -> From
+	public let forward: From -> To?
+	public let backward: To -> From
 }
 
 extension Dictionary {