diff --git a/luci-app-iperf/luasrc/controller/iperf.lua b/luci-app-iperf/luasrc/controller/iperf.lua
index 147ce4a66..a36bcd932 100644
--- a/luci-app-iperf/luasrc/controller/iperf.lua
+++ b/luci-app-iperf/luasrc/controller/iperf.lua
@@ -22,16 +22,16 @@ function run_test(server,proto,mode,updown)
 	local port = t[ math.random( #t ) ]
 	if proto == "ipv4" then
 		if updown == "upload" then
-			iperf = io.popen("iperf3 -c %s -P 10 -4 -p %s -O 3 -J" % {ut.shellquote(addr),port})
+			iperf = io.popen("iperf3 -c %s -P 10 -4 -p %s -O 3 -t 6 -J" % {ut.shellquote(addr),port})
 		else
-			iperf = io.popen("iperf3 -c %s -P 10 -4 -p %s -O 3 -R -J" % {ut.shellquote(addr),port})
+			iperf = io.popen("iperf3 -c %s -P 10 -4 -p %s -O 3 -R -t 6 -J" % {ut.shellquote(addr),port})
 		end
 		--iperf = io.popen("iperf3 -c bouygues.iperf.fr -P 10 -4 -J")
 	else
 		if updown == "upload" then
-			iperf = io.popen("iperf3 -c %s -P 10 -6 -p %s -O 3 -J" % {ut.shellquote(addr),port})
+			iperf = io.popen("iperf3 -c %s -P 10 -6 -p %s -O 3 -t 6 -J" % {ut.shellquote(addr),port})
 		else
-			iperf = io.popen("iperf3 -c %s -P 10 -6 -p %s -O 3 -R -J" % {ut.shellquote(addr),port})
+			iperf = io.popen("iperf3 -c %s -P 10 -6 -p %s -O 3 -R -t 6 -J" % {ut.shellquote(addr),port})
 		end
 	end
 	if iperf then