diff --git a/test/lib/test b/test/lib/test
index d68ade4..7259383 100755
--- a/test/lib/test
+++ b/test/lib/test
@@ -40,7 +40,7 @@ test_iperf3() {
 
 	sleep 1		# Wait for server to be ready
 
-	pane_or_context_run "${__cctx}" 				\
+	pane_or_context_run_bg "${__cctx}" 				\
 		 '('							\
 		 '	for i in $(seq 0 '${__procs}'); do'		\
 		 '		iperf3 -c '${__dest}' -p '${__port}	\
@@ -49,9 +49,12 @@ test_iperf3() {
 		 '	wait'						\
 		 ')'
 
+	sleep $((__time + 5))
+
 	# If client fails to deliver control message, tell server we're done
-	pane_or_context_run "${__sctx}" 				\
-		'sleep 2; kill -INT $(cat s*.pid); rm s*.pid'
+	pane_or_context_run "${__sctx}" 'kill -INT $(cat s*.pid); rm s*.pid'
+
+	sleep 1		# ...and wait for output to be flushed
 
 	__jval=".end.sum_received.bits_per_second"
 	for __opt in ${@}; do