diff --git a/ptxdist/configs/ecu01/barebox-defaultenv-2/bin/usb_update_rootfs b/ptxdist/configs/ecu01/barebox-defaultenv-2/bin/usb_update_rootfs
index f97666e..021549a 100755
--- a/ptxdist/configs/ecu01/barebox-defaultenv-2/bin/usb_update_rootfs
+++ b/ptxdist/configs/ecu01/barebox-defaultenv-2/bin/usb_update_rootfs
@@ -27,7 +27,15 @@ if [ -e ${image} ]; then
     do_format_ubi_var=1
     ubiattach -O 2048 /dev/nand0.var
     if [ $? -eq 0 ] ; then
-        if [ -c /dev/nand0.var.ubi.dyn ] ; then
+        #
+        # barebox bug: While [ -c /dev/nand0.var.ubi.dyn ]
+        # would be the correct test current barebox
+        # (2018.05.0-20190221-1-EAG) always returns "true"
+        # if the volume is attached, regarless whether the
+        # "dyn" partition in that volume exists or not.
+        # As fix we use [ -f /dev/nand0.var.ubi.dyn ] instead.
+        #
+        if [ -f /dev/nand0.var.ubi.dyn ] ; then
 	    echo "usb_update_rootfs: var.dyn contains data."
 	    do_format_ubi_var=0
         fi