diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 02bbf0e7a5..daf2d952e4 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -381,7 +381,7 @@ FILESEXTRAPATHS ?= "__default:"
 #  base_prefix, prefix, exec_prefix, base_bindir, base_sbindir, base_libdir,
 #  datadir, sysconfdir, servicedir, sharedstatedir, localstatedir, infodir,
 #  mandir, docdir, bindir, sbindir, libexecdir, libdir and includedir
-FILESYSTEM_PERMS_TABLES ?=  "files/fs-perms.txt \
+FILESYSTEM_PERMS_TABLES ??= "files/fs-perms.txt \
                              files/fs-perms-volatile-log.txt \
                              files/fs-perms-volatile-tmp.txt"