diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
index ab764164e1f..6c65c3d469b 100644
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -53,8 +53,8 @@
 # done
 
 # 20221109: remove rc.sendmail(8)
-OLD_FILES=etc/rc.sendmail
-OLD_FILES=share/man/man8/rc.sendmail.8.gz
+OLD_FILES+=etc/rc.sendmail
+OLD_FILES+=share/man/man8/rc.sendmail.8.gz
 
 # 20221015: update the ithread(9) man page
 OLD_FILES+=usr/share/man/man9/ithread.9.gz