diff --git a/CMakeLists.txt b/CMakeLists.txt
index efcee3b6..9743c848 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -58,7 +58,7 @@ configure_file(${PROJECT_SOURCE_DIR}/libgo/common/cmake_config.h.in ${PROJECT_SO
 message("----------------------------------")
 
 if (UNIX)
-    set(CMAKE_CXX_FLAGS "-std=c++11 -D__const__=  -fPIC -fno-strict-aliasing -Wall ${CMAKE_CXX_FLAGS}")
+    set(CMAKE_CXX_FLAGS "-std=c++11 -D__const__=__unused__  -fPIC -fno-strict-aliasing -Wall ${CMAKE_CXX_FLAGS}")
     set(CMAKE_CXX_FLAGS_DEBUG "-g")
     set(CMAKE_CXX_FLAGS_RELEASE "-g -O3 -DNDEBUG")
 
diff --git a/libgo/coroutine.h b/libgo/coroutine.h
index 03a14d4d..f97d91cd 100644
--- a/libgo/coroutine.h
+++ b/libgo/coroutine.h
@@ -1,5 +1,9 @@
 #pragma once
-#define __const__
+
+#ifndef __const__
+#define __const__ __unused__
+#endif
+
 #include "common/config.h"
 #include "common/pp.h"
 #include "common/syntax_helper.h"
diff --git a/libgo/defer/defer.h b/libgo/defer/defer.h
index ad3dc4a2..7b85987b 100644
--- a/libgo/defer/defer.h
+++ b/libgo/defer/defer.h
@@ -7,7 +7,7 @@ namespace co
     struct dismisser
     {
         virtual bool dismiss() = 0;
-
+        virtual ~dismisser() = default;
         static dismisser*& GetLastDefer();
         static void SetLastDefer(dismisser*);
         static void ClearLastDefer(dismisser*);