diff --git a/tools/releasetools/blockimgdiff.py b/tools/releasetools/blockimgdiff.py
index c95512d..c184c42 100644
--- a/tools/releasetools/blockimgdiff.py
+++ b/tools/releasetools/blockimgdiff.py
@@ -768,6 +768,7 @@
                 message.append(
                     "Fell back and generated with bsdiff instead for %s" % (
                     xf.tgt_name,))
+                xf.style = "bsdiff"
                 with lock:
                   warning_messages.extend(message)
                 del message[:]