diff --git a/runtime/base/macros.h b/runtime/base/macros.h
index fe5a2ef..fae9271 100644
--- a/runtime/base/macros.h
+++ b/runtime/base/macros.h
@@ -176,6 +176,7 @@
 #endif
 
 #define PURE __attribute__ ((__pure__))
+#define WARN_UNUSED __attribute__((warn_unused_result))
 
 template<typename T> void UNUSED(const T&) {}