diff --git a/src/h2load.cc b/src/h2load.cc
index 61048123..24276f6e 100644
--- a/src/h2load.cc
+++ b/src/h2load.cc
@@ -84,7 +84,7 @@ Config::Config()
       nreqs(1),
       nclients(1),
       nthreads(1),
-      max_concurrent_streams(-1),
+      max_concurrent_streams(1),
       window_bits(30),
       connection_window_bits(30),
       rate(0),