https://bugs.gentoo.org/327353

--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -6,7 +6,7 @@
 
 CLEANFILES = index.html compatibility.html changelog.html license.html Xdialog.1
 
-doc_DATA = index.html compatibility.html changelog.html license.html $(srcdir)/*.html $(srcdir)/*.png
+doc_DATA = $(srcdir)/*.html $(srcdir)/*.png
 
 man_MANS = Xdialog.1