diff --git a/os/gtimer/gtimer_z_unit_api_test.go b/os/gtimer/gtimer_z_unit_api_test.go
index 0ed3ec877..debc25d9c 100644
--- a/os/gtimer/gtimer_z_unit_api_test.go
+++ b/os/gtimer/gtimer_z_unit_api_test.go
@@ -102,7 +102,7 @@ func TestDelayAddEntry(t *testing.T) {
 func TestDelayAddSingleton(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
 		array := garray.New(true)
-		gtimer.DelayAddSingleton(200*time.Millisecond, 200*time.Millisecond, func() {
+		gtimer.DelayAddSingleton(500*time.Millisecond, 500*time.Millisecond, func() {
 			array.Append(1)
 			time.Sleep(10000 * time.Millisecond)
 		})
@@ -129,12 +129,12 @@ func TestDelayAddOnce(t *testing.T) {
 func TestDelayAddTimes(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
 		array := garray.New(true)
-		gtimer.DelayAddTimes(200*time.Millisecond, 200*time.Millisecond, 2, func() {
+		gtimer.DelayAddTimes(500*time.Millisecond, 500*time.Millisecond, 2, func() {
 			array.Append(1)
 		})
 		time.Sleep(300 * time.Millisecond)
 		t.Assert(array.Len(), 0)
-		time.Sleep(1000 * time.Millisecond)
+		time.Sleep(1500 * time.Millisecond)
 		t.Assert(array.Len(), 2)
 	})
 }