diff --git a/xorriso-dd-target/xorriso-dd-target b/xorriso-dd-target/xorriso-dd-target
index f4d633e9..b9e351d7 100755
--- a/xorriso-dd-target/xorriso-dd-target
+++ b/xorriso-dd-target/xorriso-dd-target
@@ -164,7 +164,8 @@ arg_interpreter() {
       min_size="$(stat -c '%s' "$i" | round_down_div_million)"
       if test -z "$min_size"
       then
-        echo "WARNING: Cannot obtain size of -image_file '$i'" >&2
+        echo "FAILURE: Cannot obtain size of -image_file '$i'" >&2
+        exit 13
       else
         min_size="$(expr $min_size + 1)"
       fi