diff --git a/external.mk b/external.mk
index 6597e1e..727b84f 100644
--- a/external.mk
+++ b/external.mk
@@ -16,6 +16,7 @@ $(call KCONFIG_ENABLE_OPT,CONFIG_NLS_ISO8859_1)
 $(call KCONFIG_ENABLE_OPT,CONFIG_NLS_UTF8)
 $(call KCONFIG_ENABLE_OPT,CONFIG_VFAT_FS)
 $(call KCONFIG_SET_OPT,CONFIG_BTRFS_FS,y)
+$(call KCONFIG_SET_OPT,CONFIG_OVERLAY_FS,y)
 $(call KCONFIG_SET_OPT,CONFIG_SQUASHFS,y)
 $(call KCONFIG_SET_OPT,CONFIG_MSDOS_FS,y)
 endef