diff --git a/adapter/http/handler.go b/adapter/http/handler.go
index 0e8e2a5..0815884 100644
--- a/adapter/http/handler.go
+++ b/adapter/http/handler.go
@@ -11,7 +11,7 @@ type HTTPAdapter struct {
 }
 
 // ServeHTTP
-func ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (a *HTTPAdapter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if r.Method != "POST" {
 		WriteError(w, 405, "rpc: POST method required, received "+r.Method)
 		return