diff --git a/CHANGELOG/CHANGELOG-3.6.md b/CHANGELOG/CHANGELOG-3.6.md
index 6512442e9..4f52e9054 100644
--- a/CHANGELOG/CHANGELOG-3.6.md
+++ b/CHANGELOG/CHANGELOG-3.6.md
@@ -63,7 +63,7 @@ See [code changes](https://github.com/etcd-io/etcd/compare/v3.5.0...v3.6.0).
 - Add [`etcd grpc-proxy --experimental-enable-grpc-logging`](https://github.com/etcd-io/etcd/pull/14266) flag to logging all grpc requests and responses.
 - Add [`etcd --experimental-compact-hash-check-enabled --experimental-compact-hash-check-time`](https://github.com/etcd-io/etcd/issues/14039) flags to support enabling reliable corruption detection on compacted revisions.
 - Add [Protection on maintenance request when auth is enabled](https://github.com/etcd-io/etcd/pull/14663).
-- Promoted [`--experimental-warning-unary-request-duration` to `--warning-unary-request-duration`](https://github.com/etcd-io/etcd/pull/14414). Note the experimental flag has already been deprecated and will be decommissioned in v3.7.
+- Graduated [`--experimental-warning-unary-request-duration` to `--warning-unary-request-duration`](https://github.com/etcd-io/etcd/pull/14414). Note the experimental flag is deprecated and will be decommissioned in v3.7.
 
 ### etcd grpc-proxy
 
diff --git a/server/etcdmain/config.go b/server/etcdmain/config.go
index 42b0da694..8adc7521f 100644
--- a/server/etcdmain/config.go
+++ b/server/etcdmain/config.go
@@ -273,7 +273,7 @@ func newConfig() *config {
 	fs.DurationVar(&cfg.ec.ExperimentalDowngradeCheckTime, "experimental-downgrade-check-time", cfg.ec.ExperimentalDowngradeCheckTime, "Duration of time between two downgrade status check.")
 	fs.DurationVar(&cfg.ec.ExperimentalWarningApplyDuration, "experimental-warning-apply-duration", cfg.ec.ExperimentalWarningApplyDuration, "Time duration after which a warning is generated if request takes more time.")
 	fs.DurationVar(&cfg.ec.WarningUnaryRequestDuration, "warning-unary-request-duration", cfg.ec.WarningUnaryRequestDuration, "Time duration after which a warning is generated if a unary request takes more time.")
-	fs.DurationVar(&cfg.ec.ExperimentalWarningUnaryRequestDuration, "experimental-warning-unary-request-duration", cfg.ec.ExperimentalWarningUnaryRequestDuration, "Time duration after which a warning is generated if a unary request takes more time. It's already deprecated, and will be decommissioned in v3.7. Use --warning-unary-request-duration instead.")
+	fs.DurationVar(&cfg.ec.ExperimentalWarningUnaryRequestDuration, "experimental-warning-unary-request-duration", cfg.ec.ExperimentalWarningUnaryRequestDuration, "Time duration after which a warning is generated if a unary request takes more time. It's deprecated, and will be decommissioned in v3.7. Use --warning-unary-request-duration instead.")
 	fs.BoolVar(&cfg.ec.ExperimentalMemoryMlock, "experimental-memory-mlock", cfg.ec.ExperimentalMemoryMlock, "Enable to enforce etcd pages (in particular bbolt) to stay in RAM.")
 	fs.BoolVar(&cfg.ec.ExperimentalTxnModeWriteWithSharedBuffer, "experimental-txn-mode-write-with-shared-buffer", true, "Enable the write transaction to use a shared buffer in its readonly check operations.")
 	fs.UintVar(&cfg.ec.ExperimentalBootstrapDefragThresholdMegabytes, "experimental-bootstrap-defrag-threshold-megabytes", 0, "Enable the defrag during etcd server bootstrap on condition that it will free at least the provided threshold of disk space. Needs to be set to non-zero value to take effect.")
diff --git a/server/etcdmain/help.go b/server/etcdmain/help.go
index 612e9f7cc..fced0130c 100644
--- a/server/etcdmain/help.go
+++ b/server/etcdmain/help.go
@@ -262,8 +262,8 @@ Experimental feature:
     Enable the write transaction to use a shared buffer in its readonly check operations.
   --experimental-bootstrap-defrag-threshold-megabytes
     Enable the defrag during etcd server bootstrap on condition that it will free at least the provided threshold of disk space. Needs to be set to non-zero value to take effect.
-  --experimental-warning-unary-request-duration '0s'
-    Set time duration after which a warning is generated if a unary request takes more than this duration. It's already deprecated, and will be decommissioned in v3.7. Use --warning-unary-request-duration instead.
+  --experimental-warning-unary-request-duration '300ms'
+    Set time duration after which a warning is generated if a unary request takes more than this duration. It's deprecated, and will be decommissioned in v3.7. Use --warning-unary-request-duration instead.
   --experimental-max-learners '1'
     Set the max number of learner members allowed in the cluster membership.
   --experimental-wait-cluster-ready-timeout '5s'
diff --git a/tests/e2e/warning_logging_test.go b/tests/e2e/promote_experimental_flag_test.go
similarity index 73%
rename from tests/e2e/warning_logging_test.go
rename to tests/e2e/promote_experimental_flag_test.go
index 139a6a4af..e794cbc6e 100644
--- a/tests/e2e/warning_logging_test.go
+++ b/tests/e2e/promote_experimental_flag_test.go
@@ -19,9 +19,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/stretchr/testify/assert"
 	"go.etcd.io/etcd/tests/v3/framework/config"
 	"go.etcd.io/etcd/tests/v3/framework/e2e"
 )
@@ -29,11 +29,10 @@ import (
 func TestWarningApplyDuration(t *testing.T) {
 	e2e.BeforeTest(t)
 
-	epc, err := e2e.NewEtcdProcessCluster(context.TODO(), t, &e2e.EtcdProcessClusterConfig{
-		ClusterSize: 1,
-		//Set very small duration to trigger warning
-		WarningUnaryRequestDuration: time.Microsecond,
-	})
+	epc, err := e2e.NewEtcdProcessCluster(context.TODO(), t,
+		e2e.WithClusterSize(1),
+		e2e.WithWarningUnaryRequestDuration(time.Microsecond),
+	)
 	if err != nil {
 		t.Fatalf("could not start etcd process cluster (%v)", err)
 	}
@@ -43,7 +42,7 @@ func TestWarningApplyDuration(t *testing.T) {
 		}
 	})
 
-	cc, err := e2e.NewEtcdctl(epc.Cfg, epc.EndpointsV3())
+	cc, err := e2e.NewEtcdctl(epc.Cfg.Client, epc.EndpointsV3())
 	require.NoError(t, err)
 	err = cc.Put(context.TODO(), "foo", "bar", config.PutOptions{})
 	assert.NoError(t, err, "error on put")
@@ -57,11 +56,10 @@ func TestWarningApplyDuration(t *testing.T) {
 func TestExperimentalWarningApplyDuration(t *testing.T) {
 	e2e.BeforeTest(t)
 
-	epc, err := e2e.NewEtcdProcessCluster(context.TODO(), t, &e2e.EtcdProcessClusterConfig{
-		ClusterSize: 1,
-		//Set very small duration to trigger warning
-		ExperimentalWarningUnaryRequestDuration: time.Microsecond,
-	})
+	epc, err := e2e.NewEtcdProcessCluster(context.TODO(), t,
+		e2e.WithClusterSize(1),
+		e2e.WithExperimentalWarningUnaryRequestDuration(time.Microsecond),
+	)
 	if err != nil {
 		t.Fatalf("could not start etcd process cluster (%v)", err)
 	}
@@ -71,7 +69,7 @@ func TestExperimentalWarningApplyDuration(t *testing.T) {
 		}
 	})
 
-	cc, err := e2e.NewEtcdctl(epc.Cfg, epc.EndpointsV3())
+	cc, err := e2e.NewEtcdctl(epc.Cfg.Client, epc.EndpointsV3())
 	require.NoError(t, err)
 	err = cc.Put(context.TODO(), "foo", "bar", config.PutOptions{})
 	assert.NoError(t, err, "error on put")
@@ -83,11 +81,11 @@ func TestExperimentalWarningApplyDuration(t *testing.T) {
 func TestBothWarningApplyDurationFlagsFail(t *testing.T) {
 	e2e.BeforeTest(t)
 
-	_, err := e2e.NewEtcdProcessCluster(context.TODO(), t, &e2e.EtcdProcessClusterConfig{
-		ClusterSize:                             1,
-		WarningUnaryRequestDuration:             time.Second,
-		ExperimentalWarningUnaryRequestDuration: time.Second,
-	})
+	_, err := e2e.NewEtcdProcessCluster(context.TODO(), t,
+		e2e.WithClusterSize(1),
+		e2e.WithWarningUnaryRequestDuration(time.Second),
+		e2e.WithExperimentalWarningUnaryRequestDuration(time.Second),
+	)
 	if err == nil {
 		t.Fatal("Expected process to fail")
 	}
diff --git a/tests/framework/e2e/cluster.go b/tests/framework/e2e/cluster.go
index 2650e156c..ee46dd6b5 100644
--- a/tests/framework/e2e/cluster.go
+++ b/tests/framework/e2e/cluster.go
@@ -313,6 +313,16 @@ func WithGoFailEnabled(enabled bool) EPClusterOption {
 	return func(c *EtcdProcessClusterConfig) { c.GoFailEnabled = enabled }
 }
 
+func WithWarningUnaryRequestDuration(time time.Duration) EPClusterOption {
+	return func(c *EtcdProcessClusterConfig) { c.WarningUnaryRequestDuration = time }
+}
+
+// WithExperimentalWarningUnaryRequestDuration sets a value for `-experimental-warning-unary-request-duration`.
+// TODO(ahrtr): remove this function when the corresponding experimental flag is decommissioned.
+func WithExperimentalWarningUnaryRequestDuration(time time.Duration) EPClusterOption {
+	return func(c *EtcdProcessClusterConfig) { c.ExperimentalWarningUnaryRequestDuration = time }
+}
+
 func WithCompactionBatchLimit(limit int) EPClusterOption {
 	return func(c *EtcdProcessClusterConfig) { c.CompactionBatchLimit = limit }
 }