diff --git a/main.go b/main.go
index 7ee4ede..38137d1 100644
--- a/main.go
+++ b/main.go
@@ -13,6 +13,7 @@ import (
 
 var addr = flag.String("addr", ":8666", "http service address")
 var tick = flag.Int("tick", 60, "")
+var timescale = flag.Float64("timescale", 1, "time scale factor")
 var verbose = flag.Bool("verbose", false, "")
 var width = flag.Float64("width", 800, "width of field")
 var height = flag.Float64("height", 550, "height of field")
@@ -42,7 +43,7 @@ func main() {
 	games = MapLock{m: make(map[string]*game)}
 	idg = NewIdGenerator()
 
-	delta = float32(*tick) / 1000
+	delta = (float32(*tick) / 1000.0) * float32(*timescale)
 
 	http.Handle("/ws/", websocket.Handler(addPlayer))
 	http.Handle("/game/start/", JsonHandler(startGame))