diff --git a/const.go b/const.go
index 50ef4c7..2d2e52d 100644
--- a/const.go
+++ b/const.go
@@ -78,3 +78,5 @@ var (
 	OutputHookStdout bool
 	OutputHookStderr bool
 )
+
+var RetryBackoff = true
diff --git a/supervisor.go b/supervisor.go
index 2d11b95..b26f64b 100644
--- a/supervisor.go
+++ b/supervisor.go
@@ -111,7 +111,10 @@ func StartSupervisor(conf *config.Config) (Supervisor, error) {
 				for cnt := 0; cnt < RetryOnceCount; cnt++ {
 					select {
 					case req := <-s.retryq:
-						delay := time.Duration(math.Pow(float64(req.Tries), 2)) * 100 * time.Millisecond
+						var delay time.Duration
+						if RetryBackoff {
+							delay = time.Duration(math.Pow(float64(req.Tries), 2)) * 100 * time.Millisecond
+						}
 						time.AfterFunc(delay, func() {
 							reqs := &[]Request{req}
 							select {
diff --git a/supervisor_test.go b/supervisor_test.go
index 708d914..205e0b2 100644
--- a/supervisor_test.go
+++ b/supervisor_test.go
@@ -58,6 +58,7 @@ func (tr TestResponseHandler) HookCmd() string {
 func init() {
 	logrus.SetLevel(logrus.WarnLevel)
 	conf.Apns.Host = gunfish.MockServer
+	gunfish.RetryBackoff = false // for testing
 }
 
 func TestEnqueuRequestToSupervisor(t *testing.T) {