diff --git a/tests/test-diffstat.t b/tests/test-diffstat.t
--- a/tests/test-diffstat.t
+++ b/tests/test-diffstat.t
@@ -35,7 +35,7 @@
 
   $ hg ci -m appenda
 
-  >>> open("c", "wb").write(b"\0")
+  >>> open("c", "wb").write(b"\0") and None
   $ touch d
   $ hg add c d
 
@@ -54,7 +54,7 @@
 
   $ hg ci -m createb
 
-  >>> open("file with spaces", "wb").write(b"\0")
+  >>> open("file with spaces", "wb").write(b"\0") and None
   $ hg add "file with spaces"
 
 Filename with spaces diffstat: