diff --git a/deps/uv/include/uv-private/uv-win.h b/deps/uv/include/uv-private/uv-win.h
index 43358da8ecc..1bd02993a84 100644
--- a/deps/uv/include/uv-private/uv-win.h
+++ b/deps/uv/include/uv-private/uv-win.h
@@ -355,6 +355,7 @@ RB_HEAD(uv_timer_tree_s, uv_timer_s);
   uv_write_t ipc_header_write_req;        \
   int ipc_pid;                            \
   uint64_t remaining_ipc_rawdata_bytes;   \
+  unsigned char reserved[sizeof(void*)];  \
   struct {                                \
     WSAPROTOCOL_INFOW* socket_info;       \
     int tcp_connection;                   \