Index: modules/http2/h2_mplx.c
===================================================================
--- modules/http2/h2_mplx.c	(revision 1816151)
+++ modules/http2/h2_mplx.c	(working copy)
@@ -658,7 +658,11 @@
 static void register_if_needed(h2_mplx *m) 
 {
     if (!m->aborted && !m->is_registered && !h2_iq_empty(m->q)) {
-        apr_status_t status = h2_workers_register(m->workers, m); 
+        apr_status_t status;
+        
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
+                      "h2_mplx(%ld): need to register at workers", m->id);
+        status = h2_workers_register(m->workers, m); 
         if (status == APR_SUCCESS) {
             m->is_registered = 1;
         }
Index: modules/http2/h2_workers.c
===================================================================
--- modules/http2/h2_workers.c	(revision 1816151)
+++ modules/http2/h2_workers.c	(working copy)
@@ -305,7 +305,7 @@
     workers->max_workers = max_workers;
     workers->max_idle_secs = (idle_secs > 0)? idle_secs : 10;
 
-    status = h2_fifo_create(&workers->mplxs, pool, 2 * workers->max_workers);
+    status = h2_fifo_set_create(&workers->mplxs, pool, 2 * workers->max_workers);
     if (status != APR_SUCCESS) {
         return NULL;
     }