diff --git a/dm/dm/master/openapi_test.go b/dm/dm/master/openapi_test.go
index 9638136fa99..453a485bdce 100644
--- a/dm/dm/master/openapi_test.go
+++ b/dm/dm/master/openapi_test.go
@@ -93,10 +93,11 @@ func (t *openAPISuite) TestRedirectRequestToLeader(c *check.C) {
 	s1 := NewServer(cfg1)
 	c.Assert(s1.Start(ctx), check.IsNil)
 	defer s1.Close()
+	defer cancel()
 
 	// wait the first one become the leader
 	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-		return s1.election.IsLeader()
+		return s1.election.IsLeader() && s1.scheduler.Started()
 	}), check.IsTrue)
 
 	// join to an existing cluster
@@ -113,6 +114,12 @@ func (t *openAPISuite) TestRedirectRequestToLeader(c *check.C) {
 	s2 := NewServer(cfg2)
 	c.Assert(s2.Start(ctx), check.IsNil)
 	defer s2.Close()
+	defer cancel() // this cancel must call before s.Close() to avoid deadlock
+
+	// wait the second master ready
+	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
+		return s2.election.IsLeader()
+	}), check.IsFalse)
 
 	baseURL := "/api/v1/sources"
 	// list source from leader
@@ -128,7 +135,6 @@ func (t *openAPISuite) TestRedirectRequestToLeader(c *check.C) {
 	// list source not from leader will get a redirect
 	result2 := testutil.NewRequest().Get(baseURL).GoWithHTTPHandler(t.testT, s2.openapiHandles)
 	c.Assert(result2.Code(), check.Equals, http.StatusTemporaryRedirect)
-	cancel()
 }
 
 func (t *openAPISuite) TestOpenAPIWillNotStartInDefaultConfig(c *check.C) {
@@ -151,7 +157,7 @@ func (t *openAPISuite) TestOpenAPIWillNotStartInDefaultConfig(c *check.C) {
 	}), check.IsTrue)
 	c.Assert(s1.openapiHandles, check.IsNil)
 	defer s1.Close()
-	cancel()
+	defer cancel()
 }
 
 func (t *openAPISuite) TestSourceAPI(c *check.C) {