diff --git a/omaha_request_action.h b/omaha_request_action.h
index 0f066e3..307798b 100644
--- a/omaha_request_action.h
+++ b/omaha_request_action.h
@@ -42,6 +42,7 @@
   off_t size;
   bool needs_admin;
   bool prompt;
+  bool is_delta;
 };
 COMPILE_ASSERT(sizeof(off_t) == 8, off_t_not_64bit);