diff --git a/src/HttpResponse.h b/src/HttpResponse.h
index 691caf1..dd3dd5f 100644
--- a/src/HttpResponse.h
+++ b/src/HttpResponse.h
@@ -231,10 +231,10 @@ public:
     }
 
     /* Attach handler for writable HTTP response */
-    HttpResponse *onWritable(fu2::unique_function<bool(int)> handler) {
+    HttpResponse *onWritable(fu2::unique_function<bool(int)> &&handler) {
         HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
 
-        httpResponseData->onWritable = handler;
+        httpResponseData->onWritable = std::move(handler);
         return this;
     }
 
diff --git a/uSockets b/uSockets
index 2e61980..b876997 160000
--- a/uSockets
+++ b/uSockets
@@ -1 +1 @@
-Subproject commit 2e6198067a8702f51e87e64709b98c0c9ca0fa2f
+Subproject commit b8769978449f9509314cd7b6b981e630ff312a21