diff --git a/server/config.go b/server/config.go
index bdfce016991..2eada20a6e7 100644
--- a/server/config.go
+++ b/server/config.go
@@ -316,9 +316,27 @@ func (m *configMetaData) Child(path ...string) *configMetaData {
 	}
 }
 
+func (m *configMetaData) CheckUndecoded() error {
+	if m.meta == nil {
+		return nil
+	}
+	undecoded := m.meta.Undecoded()
+	if len(undecoded) == 0 {
+		return nil
+	}
+	errInfo := "Config contains undefined item: "
+	for _, key := range undecoded {
+		errInfo += key.String() + ", "
+	}
+	return errors.New(errInfo[:len(errInfo)-2])
+}
+
 // Adjust is used to adjust the PD configurations.
 func (c *Config) Adjust(meta *toml.MetaData) error {
 	configMetaData := newConfigMetadata(meta)
+	if err := configMetaData.CheckUndecoded(); err != nil {
+		return err
+	}
 
 	if c.Name == "" {
 		hostname, err := os.Hostname()
diff --git a/server/config_test.go b/server/config_test.go
index d67e6aaf029..6af01dabafc 100644
--- a/server/config_test.go
+++ b/server/config_test.go
@@ -114,4 +114,19 @@ leader-schedule-limit = 0
 	// When undefined, use default values.
 	c.Assert(cfg.PreVote, IsTrue)
 	c.Assert(cfg.Schedule.MaxMergeRegionKeys, Equals, uint64(defaultMaxMergeRegionKeys))
+
+	// Check undefined config fields
+	cfgData = `
+type = "pd"
+name = ""
+lease = 0
+
+[schedule]
+type = "random-merge"
+`
+	cfg = NewConfig()
+	meta, err = toml.Decode(cfgData, &cfg)
+	c.Assert(err, IsNil)
+	err = cfg.Adjust(&meta)
+	c.Assert(err, NotNil)
 }
diff --git a/server/coordinator.go b/server/coordinator.go
index 396163a9335..b7d4c824b53 100644
--- a/server/coordinator.go
+++ b/server/coordinator.go
@@ -199,12 +199,11 @@ func (c *coordinator) run() {
 		}
 		s, err := schedule.CreateScheduler(schedulerCfg.Type, c.opController, schedulerCfg.Args...)
 		if err != nil {
-			log.Errorf("can not create scheduler %s: %v", schedulerCfg.Type, err)
-		} else {
-			log.Infof("create scheduler %s", s.GetName())
-			if err = c.addScheduler(s, schedulerCfg.Args...); err != nil {
-				log.Errorf("can not add scheduler %s: %v", s.GetName(), err)
-			}
+			log.Fatalf("can not create scheduler %s: %v", schedulerCfg.Type, err)
+		}
+		log.Infof("create scheduler %s", s.GetName())
+		if err = c.addScheduler(s, schedulerCfg.Args...); err != nil {
+			log.Errorf("can not add scheduler %s: %v", s.GetName(), err)
 		}
 
 		// only record valid scheduler config