diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 3cd82563d..1295230d0 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -1286,7 +1286,20 @@ class BlockDifference(object):
     else:
       ranges = self.src.care_map.subtract(self.src.clobbered_blocks)
       ranges_str = ranges.to_string_raw()
-      if self.version >= 3:
+      if self.version >= 4:
+        script.AppendExtra(('if (range_sha1("%s", "%s") == "%s" || '
+                            'block_image_verify("%s", '
+                            'package_extract_file("%s.transfer.list"), '
+                            '"%s.new.dat", "%s.patch.dat") || '
+                            '(block_image_recover("%s", "%s") && '
+                            'block_image_verify("%s", '
+                            'package_extract_file("%s.transfer.list"), '
+                            '"%s.new.dat", "%s.patch.dat"))) then') % (
+                            self.device, ranges_str, self.src.TotalSha1(),
+                            self.device, partition, partition, partition,
+                            self.device, ranges_str,
+                            self.device, partition, partition, partition))
+      elif self.version == 3:
         script.AppendExtra(('if (range_sha1("%s", "%s") == "%s" || '
                             'block_image_verify("%s", '
                             'package_extract_file("%s.transfer.list"), '