diff --git a/tools/releasetools/make_recovery_patch b/tools/releasetools/make_recovery_patch
index 765063a..470dfc4 100755
--- a/tools/releasetools/make_recovery_patch
+++ b/tools/releasetools/make_recovery_patch
@@ -39,6 +39,9 @@
   boot_img = common.GetBootableImage("boot.img", "boot.img",
                                      input_dir, "BOOT")
 
+  if not recovery_img or not boot_img:
+    sys.exit(0)
+
   def output_sink(fn, data):
     with open(os.path.join(output_dir, "SYSTEM", *fn.split("/")), "wb") as f:
       f.write(data)