diff --git a/configure.ac b/configure.ac
index 1155cfe..0165e08 100755
--- a/configure.ac
+++ b/configure.ac
@@ -96,6 +96,8 @@
     [The base dir where all RO partitions are mounted])
 AC_DEFINE(BMC_ROFS_PREFIX, "/media/rofs-",
     [The prefix path for the versioned read-only bmc partitions])
+AC_DEFINE(ALT_RWFS, "/media/alt/var/persist",
+    [The path of the alt rwfs overlay])
 AC_DEFINE(PERSIST_DIR, "/var/lib/obmc/phosphor-bmc-code-mgmt/",
     [The dir where activation data is stored in files])
 AC_DEFINE(SYSTEMD_BUSNAME, "org.freedesktop.systemd1",