1 files changed, 4 insertions, 2 deletions
diff --git a/qemu-img.c b/qemu-img.c
index 7956a89965..ec0e2fabe5 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2508,8 +2508,10 @@ static int img_convert(int argc, char **argv)
 
     if (out_baseimg_param) {
         if (!qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT)) {
-            warn_report("Deprecated use of backing file without explicit "
-                        "backing format");
+            error_report("Use of backing file requires explicit "
+                         "backing format");
+            ret = -1;
+            goto out;
         }
     }