diff --git a/src/Patch.hs b/src/Patch.hs
index 9c212d11c..402783dbc 100644
--- a/src/Patch.hs
+++ b/src/Patch.hs
@@ -16,6 +16,7 @@ module Patch
 , patchType
 ) where
 
+import Data.Align
 import Data.Functor.Listable
 import Data.These
 import Prologue
@@ -90,3 +91,8 @@ instance Listable1 Patch where
 
 instance Listable a => Listable (Patch a) where
   tiers = tiers1
+
+instance Crosswalk Patch where
+  crosswalk f (Replace a b) = alignWith (these Delete Insert Replace) (f a) (f b)
+  crosswalk f (Insert b) = Insert <$> f b
+  crosswalk f (Delete a) = Delete <$> f a