diff --git a/lwlib/Makefile.in b/lwlib/Makefile.in
index 7a3eb8fd815..51b13040b9c 100644
--- a/lwlib/Makefile.in
+++ b/lwlib/Makefile.in
@@ -70,6 +70,6 @@ distclean: clean
 maintainer-clean: distclean
 
 TAGS:
-	../lib-src/etags -t *.[ch]
+	../lib-src/etags -t $(srcdir)/*.[ch]
 tags: TAGS
 .PHONY: tags