diff --git a/lib/am/distdir.am b/lib/am/distdir.am
index 35aad4f..bc0774c 100644
--- a/lib/am/distdir.am
+++ b/lib/am/distdir.am
@@ -298,7 +298,7 @@ distcheck: dist
 ## Make the new source tree read-only.  Distributions ought to work in
 ## this case.  However, make the top-level directory writable so we
 ## can make our new subdirs.
-	chmod -R a-w $(distdir); chmod a+w $(distdir)
+	chmod -R a-w $(distdir); chmod u+w $(distdir)
 	mkdir $(distdir)/_build
 	mkdir $(distdir)/_inst
 ## Undo the write access.