--- Makefile.am.orig	2017-06-09 19:33:36 UTC
+++ Makefile.am
@@ -13,12 +13,13 @@ SUBDIRS = \
 	extra
 
 EXTRA_DIST = \
-	COPYING \
-	LICENSE_CC_BY_SA4 \
 	README.md
 
 install-data-hook:
-	cp -Rv $(EXTRA_DIST) $(adaptadir)
+	if test ! -z "$(ADAPTA_DOCS)"; then \
+	mkdir -p $(DESTDIR)$(docdir); \
+	cp -Rv $(EXTRA_DIST) $(DESTDIR)$(docdir); \
+	fi
 
 uninstall-hook:
 	test -e $(noktodir) && rm -rfv $(noktodir)