diff --git a/payload_consumer/postinstall_runner_action.cc b/payload_consumer/postinstall_runner_action.cc
index 1ada63b..e7804ea 100644
--- a/payload_consumer/postinstall_runner_action.cc
+++ b/payload_consumer/postinstall_runner_action.cc
@@ -181,6 +181,7 @@
   EnsureUnmounted();
 
 #ifdef __ANDROID__
+#ifdef USE_WEEKLY_BUILD
   // Check the currently installed /system partition to see if it's ever
   // been mounted R/W. If it has, we'll run backuptool scripts for it
   // since we can safely assume something on the partition has been
@@ -247,6 +248,7 @@
   }
 
   utils::UnmountFilesystem(fs_mount_dir_);
+#endif  // USE_WEEKLY_BUILD
 
   // In Chromium OS, the postinstall step is allowed to write to the block
   // device on the target image, so we don't mark it as read-only and should