diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 3944af5..7196c48 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -1422,6 +1422,10 @@
     return
 
   sh = """#!/system/bin/sh
+if [ -f /system/etc/recovery-transform.sh ]; then
+  exec sh /system/etc/recovery-transform.sh %(recovery_size)d %(recovery_sha1)s %(boot_size)d %(boot_sha1)s
+fi
+
 if ! applypatch -c %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s; then
   applypatch %(bonus_args)s %(boot_type)s:%(boot_device)s:%(boot_size)d:%(boot_sha1)s %(recovery_type)s:%(recovery_device)s %(recovery_sha1)s %(recovery_size)d %(boot_sha1)s:/system/recovery-from-boot.p && log -t recovery "Installing new recovery image: succeeded" || log -t recovery "Installing new recovery image: failed"
 else