diff --git a/docs/log-message-tags/next-number b/docs/log-message-tags/next-number
index 1487908673..46cff15d5b 100644
--- a/docs/log-message-tags/next-number
+++ b/docs/log-message-tags/next-number
@@ -1 +1 @@
-3408
+3409
diff --git a/modules/proxy/proxy_util.c b/modules/proxy/proxy_util.c
index cfda405195..6f8849d530 100644
--- a/modules/proxy/proxy_util.c
+++ b/modules/proxy/proxy_util.c
@@ -2768,7 +2768,7 @@ PROXY_DECLARE(int) ap_proxy_connect_backend(const char *proxy_function,
                              proxy_function);
             }
             else {
-                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO()
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(03408)
                              "%s: reusable backend connection is not empty: "
                              "forcibly closed", proxy_function);
                 connected = 0;