diff --git a/f8/httpclientpool.h b/f8/httpclientpool.h
index d990d5c..29dbc65 100644
--- a/f8/httpclientpool.h
+++ b/f8/httpclientpool.h
@@ -3,6 +3,9 @@
 namespace f8
 {
 
+    struct HttpContext;
+    typedef std::function<void(bool, a8::XObject*, f8::HttpContext*)> HttpProxyCb;
+
     typedef void (*AsyncHttpOnOkFunc)(a8::XParams& param, a8::XObject& data);
     typedef void (*AsyncHttpOnErrorFunc)(a8::XParams& param, const std::string& response);