diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index cc10267..462c3bf 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -2619,7 +2619,9 @@
     device = p.device
     if "/" in device:
       device = device[device.rfind("/")+1:]
-    limit = info_dict.get(device + "_size")
+    limit = info_dict.get(device + "_size", 0)
+    if isinstance(limit, str):
+      limit = int(limit, 0)
   if not fs_type or not limit:
     return