diff --git a/configure.ac b/configure.ac
index b5108d48a..1aa7ed064 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,7 +25,7 @@
 
 # Initialize the autoconf system for the specified tool, version and mailing list
 AC_PREREQ([2.71])
-AC_INIT([iperf],[3.15],[https://github.com/esnet/iperf],[iperf],[https://software.es.net/iperf/])
+AC_INIT([iperf],[3.15-mt],[https://github.com/esnet/iperf],[iperf],[https://software.es.net/iperf/])
 m4_include([config/ax_check_openssl.m4])
 m4_include([config/ax_pthread.m4])
 m4_include([config/iperf_config_static_bin.m4])