diff --git a/src/node_http2_core-inl.h b/src/node_http2_core-inl.h
index eda8a93ee79ff0..c78e5d673f41f4 100644
--- a/src/node_http2_core-inl.h
+++ b/src/node_http2_core-inl.h
@@ -503,7 +503,7 @@ inline void Nghttp2Session::SendPendingData() {
   while ((srcLength = nghttp2_session_mem_send(session_, &src)) > 0) {
     if (req == nullptr) {
       req = AllocateSend();
-      destRemaining = req->self_size();
+      destRemaining = req->ExtraSize();
       dest = req->Extra();
     }
     DEBUG_HTTP2("Nghttp2Session %s: nghttp2 has %d bytes to send\n",
@@ -525,7 +525,7 @@ inline void Nghttp2Session::SendPendingData() {
       srcRemaining -= destRemaining;
       srcOffset += destRemaining;
       req = AllocateSend();
-      destRemaining = req->self_size();
+      destRemaining = req->ExtraSize();
       dest = req->Extra();
     }
 
diff --git a/src/stream_base-inl.h b/src/stream_base-inl.h
index 667c0a9ffbd50d..e1e50802f2a06a 100644
--- a/src/stream_base-inl.h
+++ b/src/stream_base-inl.h
@@ -160,6 +160,10 @@ char* WriteWrap::Extra(size_t offset) {
          offset;
 }
 
+size_t WriteWrap::ExtraSize() const {
+  return storage_size_ - ROUND_UP(sizeof(*this), kAlignSize);
+}
+
 }  // namespace node
 
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
diff --git a/src/stream_base.h b/src/stream_base.h
index 9833a82636d28e..20cb0155c9d7b9 100644
--- a/src/stream_base.h
+++ b/src/stream_base.h
@@ -77,6 +77,7 @@ class WriteWrap: public ReqWrap<uv_write_t>,
                                size_t extra = 0);
   inline void Dispose();
   inline char* Extra(size_t offset = 0);
+  inline size_t ExtraSize() const;
 
   inline StreamBase* wrap() const { return wrap_; }