diff --git a/lib/http2.c b/lib/http2.c
index 75956a02121d3fa4e70c4c800de807aa092204cc..d4bc82afabbe747051db4f7fc4f84bf8c28f8507 100644
--- a/lib/http2.c
+++ b/lib/http2.c
@@ -400,6 +400,7 @@ static const nghttp2_session_callbacks callbacks = {
   on_header              /* nghttp2_on_header_callback */
 #if NGHTTP2_VERSION_NUM >= 0x000400
   , NULL                 /* nghttp2_select_padding_callback */
+  , NULL                 /* nghttp2_adjust_priority_callback */
 #endif
 };