diff --git a/scripts/enable-hibernation.sh b/scripts/enable-hibernation.sh
index a1fe9a0..eba5fe5 100755
--- a/scripts/enable-hibernation.sh
+++ b/scripts/enable-hibernation.sh
@@ -13,6 +13,7 @@ fi
 SWAPFILE=/swapfile
 SWAPSIZE=16g
 ROOT_PARTUUID=$(findmnt -no PARTUUID /)
+[ -n "$ROOT_PARTUUID" ] || { echo "ERROR: could not determine root PARTUUID via findmnt." >&2; exit 1; }
 
 echo "==> Step 1/6: ensure swap file exists at $SWAPFILE (size $SWAPSIZE)"
 if [ ! -f "$SWAPFILE" ]; then