diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 5e5b856..2e3138c 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -144,7 +144,7 @@
 
   tmp = tempfile.mkdtemp(prefix="targetfiles-")
   OPTIONS.tempfiles.append(tmp)
-  p = Run(["unzip", "-q", filename, "-d", tmp], stdout=subprocess.PIPE)
+  p = Run(["unzip", "-o", "-q", filename, "-d", tmp], stdout=subprocess.PIPE)
   p.communicate()
   if p.returncode != 0:
     raise ExternalError("failed to unzip input target-files \"%s\"" %