diff --git a/quartz/cron_test.go b/quartz/cron_test.go
index 759e504..10cc57a 100644
--- a/quartz/cron_test.go
+++ b/quartz/cron_test.go
@@ -299,7 +299,27 @@ func iterate(prev int64, cronTrigger *quartz.CronTrigger, iterations int) (strin
 
 func TestCronExpressionError(t *testing.T) {
 	tests := []string{
+		"-1 * * * * *",
+		"X * * * * *",
+		"* X * * * *",
+		"* * X * * *",
+		"* * * X * *",
+		"* * * * X *",
+		"* * * * * X",
+		"* * * * * * X",
+		"1,X/1 * * * * *",
+		"1,X-1 * * * * *",
+		"1-2-3 * * * * *",
+		"X-2 * * * * *",
+		"1-X * * * * *",
+		"100-200 * * * * *",
+		"1/2/3 * * * * *",
+		"1-2-3/4 * * * * *",
+		"X-2/4 * * * * *",
+		"1-X/4 * * * * *",
+		"X/4 * * * * *",
 		"*/X * * * * *",
+		"200/100 * * * * *",
 	}
 	for _, test := range tests {
 		t.Run(test, func(t *testing.T) {
diff --git a/quartz/job_key_test.go b/quartz/job_key_test.go
index 7de9d87..645fa62 100644
--- a/quartz/job_key_test.go
+++ b/quartz/job_key_test.go
@@ -11,9 +11,13 @@ import (
 func TestJobKey(t *testing.T) {
 	name := "jobName"
 	jobKey1 := quartz.NewJobKey(name)
+	assert.Equal(t, jobKey1.Name(), name)
+	assert.Equal(t, jobKey1.Group(), quartz.DefaultGroup)
 	assert.Equal(t, jobKey1.String(), fmt.Sprintf("%s::%s", quartz.DefaultGroup, name))
 
 	jobKey2 := quartz.NewJobKeyWithGroup(name, "")
+	assert.Equal(t, jobKey2.Name(), name)
+	assert.Equal(t, jobKey2.Group(), quartz.DefaultGroup)
 	assert.Equal(t, jobKey2.String(), fmt.Sprintf("%s::%s", quartz.DefaultGroup, name))
 
 	if !jobKey1.Equals(jobKey2) {
diff --git a/quartz/scheduler_test.go b/quartz/scheduler_test.go
index a626898..6476726 100644
--- a/quartz/scheduler_test.go
+++ b/quartz/scheduler_test.go
@@ -13,6 +13,7 @@ import (
 	"github.com/reugn/go-quartz/internal/assert"
 	"github.com/reugn/go-quartz/internal/mock"
 	"github.com/reugn/go-quartz/job"
+	"github.com/reugn/go-quartz/matcher"
 	"github.com/reugn/go-quartz/quartz"
 )
 
@@ -307,6 +308,11 @@ func TestScheduler_JobWithRetries(t *testing.T) {
 	)
 	err := sched.ScheduleJob(jobDetail, quartz.NewRunOnceTrigger(time.Millisecond))
 	assert.IsNil(t, err)
+	err = sched.ScheduleJob(jobDetail, quartz.NewRunOnceTrigger(time.Millisecond))
+	assert.ErrorIs(t, err, quartz.ErrIllegalState)
+	jobDetail.Options().Replace = true
+	err = sched.ScheduleJob(jobDetail, quartz.NewRunOnceTrigger(time.Millisecond))
+	assert.IsNil(t, err)
 
 	assert.Equal(t, funcRetryJob.JobStatus(), job.StatusNA)
 	assert.Equal(t, int(atomic.LoadInt32(&n)), 0)
@@ -425,6 +431,10 @@ func TestScheduler_PauseResumeErrors(t *testing.T) {
 	err = sched.PauseJob(quartz.NewJobKey("funcJob2"))
 	assert.ErrorIs(t, err, quartz.ErrJobNotFound)
 
+	assert.Equal(t, len(sched.GetJobKeys(matcher.JobPaused())), 1)
+	assert.Equal(t, len(sched.GetJobKeys(matcher.JobActive())), 0)
+	assert.Equal(t, len(sched.GetJobKeys()), 1)
+
 	sched.Stop()
 }