diff --git a/src/testdir/test77.in b/src/testdir/test77.in
index 441845c..8ac7e10 100644
--- a/src/testdir/test77.in
+++ b/src/testdir/test77.in
@@ -21,7 +21,9 @@
 :while i <= 2000000 | call append(i, range(i, i + 99)) | let i += 100 | endwhile
 ggdd
 :w! Xtest
-:!cksum Xtest > test.out
+:r !cksum Xtest
+:s/\s/ /g
+:.w! test.out
 :qa!
 ENDTEST