diff -Nru tnftp-20151004/debian/rules tnftp-20151004/debian/rules
--- tnftp-20151004/debian/rules	2020-05-10 16:01:50.000000000 +0200
+++ tnftp-20151004/debian/rules	2020-05-10 16:01:50.000000000 +0200
@@ -17,6 +17,7 @@
 build: build-stamp
 build-stamp:
 	dh_testdir
+	dh_update_autotools_config
 	./configure --prefix=/usr --mandir=\$${prefix}/share/man
 	$(MAKE)
 	touch build-stamp
