diff --git a/internal/app/util.go b/internal/app/util.go
index 1b71b020..bedda991 100644
--- a/internal/app/util.go
+++ b/internal/app/util.go
@@ -236,21 +236,28 @@ func isGTIDLessOrEqual(slaveGtidSet, masterGtidSet gtids.GTIDSet) bool {
 }
 
 func isSplitBrained(slaveGtidSet, masterGtidSet *gomysql.MysqlGTIDSet, masterUUID uuid.UUID) bool {
-	for _, MasterSet := range masterGtidSet.Sets {
-		slaveSet, ok := slaveGtidSet.Sets[MasterSet.SID.String()]
+	for _, masterSet := range masterGtidSet.Sets {
+		slaveSet, ok := slaveGtidSet.Sets[masterSet.SID.String()]
 		if !ok {
 			continue
 		}
-		if MasterSet.Contain(slaveSet) || MasterSet == slaveSet {
+		if masterSet.Contain(slaveSet) || masterSet == slaveSet {
 			continue
 		}
 
-		if MasterSet.SID == masterUUID {
+		if masterSet.SID == masterUUID {
 			continue
 		}
 
 		return true
 	}
+
+	for _, slaveSet := range slaveGtidSet.Sets {
+		if _, ok := masterGtidSet.Sets[slaveSet.SID.String()]; !ok {
+			return true
+		}
+	}
+
 	return false
 }
 
diff --git a/internal/app/util_test.go b/internal/app/util_test.go
index 8a71e8cb..015b90be 100644
--- a/internal/app/util_test.go
+++ b/internal/app/util_test.go
@@ -327,3 +327,52 @@ func getLogger() *log.Logger {
 	}
 	return l
 }
+
+func TestIsSplitBrained(t *testing.T) {
+	masterGTID, _ := gomysql.ParseMysqlGTIDSet("6DBC0B04-4B09-43DC-86CC-9AF852DED919:1-100," +
+		"09978591-5754-4710-BF67-062880ABE1B4:1-100," +
+		"AA6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-100")
+	masterMySQLGTID := masterGTID.(*gomysql.MysqlGTIDSet)
+	masterUUID := masterMySQLGTID.Sets["6dbc0b04-4b09-43dc-86cc-9af852ded919"].SID
+
+	// equal gtids
+	slaveGTID, _ := gomysql.ParseMysqlGTIDSet("6DBC0B04-4B09-43DC-86CC-9AF852DED919:1-101," +
+		"09978591-5754-4710-BF67-062880ABE1B4:1-100," +
+		"AA6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-100")
+	slaveMySQLGTID := slaveGTID.(*gomysql.MysqlGTIDSet)
+	ok := isSplitBrained(slaveMySQLGTID, masterMySQLGTID, masterUUID)
+	require.False(t, ok)
+
+	// the replica is lagging behind the master
+	slaveGTID, _ = gomysql.ParseMysqlGTIDSet("6DBC0B04-4B09-43DC-86CC-9AF852DED919:1-99," +
+		"09978591-5754-4710-BF67-062880ABE1B4:1-100," +
+		"AA6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-100")
+	slaveMySQLGTID = slaveGTID.(*gomysql.MysqlGTIDSet)
+	ok = isSplitBrained(slaveMySQLGTID, masterMySQLGTID, masterUUID)
+	require.False(t, ok)
+
+	// the replica applied the transaction from the master before the master
+	slaveGTID, _ = gomysql.ParseMysqlGTIDSet("6DBC0B04-4B09-43DC-86CC-9AF852DED919:1-101," +
+		"09978591-5754-4710-BF67-062880ABE1B4:1-100," +
+		"AA6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-100")
+	slaveMySQLGTID = slaveGTID.(*gomysql.MysqlGTIDSet)
+	ok = isSplitBrained(slaveMySQLGTID, masterMySQLGTID, masterUUID)
+	require.False(t, ok)
+
+	// the replica applied a transaction not from the master
+	slaveGTID, _ = gomysql.ParseMysqlGTIDSet("6DBC0B04-4B09-43DC-86CC-9AF852DED919:1-100," +
+		"09978591-5754-4710-BF67-062880ABE1B4:1-100," +
+		"AA6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-101")
+	slaveMySQLGTID = slaveGTID.(*gomysql.MysqlGTIDSet)
+	ok = isSplitBrained(slaveMySQLGTID, masterMySQLGTID, masterUUID)
+	require.True(t, ok)
+
+	// the replica applied a new transaction not from the master
+	slaveGTID, _ = gomysql.ParseMysqlGTIDSet("6DBC0B04-4B09-43DC-86CC-9AF852DED919:1-101," +
+		"09978591-5754-4710-BF67-062880ABE1B4:1-100," +
+		"AA6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-100," +
+		"BB6890C8-69F8-4BC4-B3A5-5D3FEA8C28CF:1-100")
+	slaveMySQLGTID = slaveGTID.(*gomysql.MysqlGTIDSet)
+	ok = isSplitBrained(slaveMySQLGTID, masterMySQLGTID, masterUUID)
+	require.True(t, ok)
+}