diff --git a/tools/releasetools/img_from_target_files b/tools/releasetools/img_from_target_files
index ec6e7c6..3a52342 100755
--- a/tools/releasetools/img_from_target_files
+++ b/tools/releasetools/img_from_target_files
@@ -58,7 +58,7 @@
   image_props = build_image.ImagePropFromGlobalDict(OPTIONS.info_dict,
                                                     "data")
   # If no userdata_size is provided, skip userdata.img.
-  if not image_props.get("userdata_size"):
+  if not image_props.get("partition_size"):
     return
 
   print "creating userdata.img..."