--- Makefile.am.orig	2018-01-01 03:20:16 UTC
+++ Makefile.am
@@ -5,12 +5,13 @@ SUBDIRS = \
 	backgrounds
 
 EXTRA_DIST = \
-	AUTHORS \
-	COPYING \
-	LICENSE_CC_BY_SA4
+	AUTHORS
 
 install-data-hook:
-	cp -Rv $(EXTRA_DIST) $(adaptadir)
+	if test ! -z "$(ADAPTA_BG_DOCS)"; then \
+	mkdir -p $(DESTDIR)$(docdir); \
+	cp -Rv $(EXTRA_DIST) $(DESTDIR)$(docdir); \
+	fi;
 
 uninstall-hook:
 	test -e $(adaptadir) && rm -rfv $(adaptadir)