diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py
index 9049622..7fdf4ba 100755
--- a/tools/releasetools/build_image.py
+++ b/tools/releasetools/build_image.py
@@ -814,16 +814,18 @@
 
 
 def main(argv):
-  if len(argv) != 4:
+  args = common.ParseOptions(argv, __doc__)
+
+  if len(args) != 4:
     print(__doc__)
     sys.exit(1)
 
   common.InitLogging()
 
-  in_dir = argv[0]
-  glob_dict_file = argv[1]
-  out_file = argv[2]
-  target_out = argv[3]
+  in_dir = args[0]
+  glob_dict_file = args[1]
+  out_file = args[2]
+  target_out = args[3]
 
   glob_dict = LoadGlobalDict(glob_dict_file)
   if "mount_point" in glob_dict: