diff --git a/board/czechlight/clearfog/overlay/etc/rauc/system.conf b/board/czechlight/clearfog/overlay/etc/rauc/system.conf
index 11cf7c5..8adc7f9 100644
--- a/board/czechlight/clearfog/overlay/etc/rauc/system.conf
+++ b/board/czechlight/clearfog/overlay/etc/rauc/system.conf
@@ -14,6 +14,7 @@
 
 [slot.rootfs.1]
 device=/dev/mmcblk0p3
+type=ext4
 bootname=B
 
 [slot.cfg.1]