diff --git a/test/AlignmentSpec.hs b/test/AlignmentSpec.hs
index c6cd250f4..9b68959a5 100644
--- a/test/AlignmentSpec.hs
+++ b/test/AlignmentSpec.hs
@@ -103,4 +103,4 @@ leaf info = Free . Annotated info . Leaf
 info :: Int -> Int -> Info
 info = ((\ r -> Info r mempty 0) .) . Range
 
-newtype PrettyDiff = PrettyDiff { unPrettyDiff :: Join These [SplitDiff String Info] }
+data PrettyDiff = PrettyDiff { unPrettySource :: Source.Source Char, unPrettyDiff :: [Join These (SplitDiff String Info)] }