diff --git a/include/sta/event.hpp b/include/sta/event.hpp
index 56b05a9..019f8ad 100644
--- a/include/sta/event.hpp
+++ b/include/sta/event.hpp
@@ -41,6 +41,8 @@ namespace sta
          * @param timeout timeout in ms., default to forever.
          */
         virtual uint32_t wait(uint32_t flags, uint32_t timeout = osWaitForever) = 0;
+
+        virtual uint32_t waitAll(uint32_t flags, uint32_t timeout = osWaitForever) = 0;
     };
 } // namespace sta