diff --git a/src/Diffing.hs b/src/Diffing.hs
index bbedd5be6..8d5344186 100644
--- a/src/Diffing.hs
+++ b/src/Diffing.hs
@@ -114,10 +114,10 @@ writeToOutput output text =
     Nothing -> do
       lang <- lookupEnv "LANG"
       case lang of
-	-- If LANG is set and isn't the empty string, leave the encoding.
-	Just x | x /= "" -> pure ()
-	-- Otherwise default to utf8.
-	_ -> IO.hSetEncoding IO.stdout IO.utf8
+        -- If LANG is set and isn't the empty string, leave the encoding.
+        Just x | x /= "" -> pure ()
+        -- Otherwise default to utf8.
+        _ -> IO.hSetEncoding IO.stdout IO.utf8
       TextIO.hPutStrLn IO.stdout text
     Just path -> do
       isDir <- doesDirectoryExist path