diff --git a/etcdserver/api/capability.go b/etcdserver/api/capability.go
index 8b13f474295..9a8e280c13e 100644
--- a/etcdserver/api/capability.go
+++ b/etcdserver/api/capability.go
@@ -41,6 +41,8 @@ var (
 		"3.2.0": {AuthCapability: true, V3rpcCapability: true},
 		"3.3.0": {AuthCapability: true, V3rpcCapability: true},
 		"3.4.0": {AuthCapability: true, V3rpcCapability: true},
+		//TODO: use EnableCapability and flag to control this dynamically
+		"3.5.0": {AuthCapability: true, V3rpcCapability: true},
 	}
 
 	enableMapMu sync.RWMutex
diff --git a/etcdserver/api/membership/cluster.go b/etcdserver/api/membership/cluster.go
index ae1a5608005..0d0277d3046 100644
--- a/etcdserver/api/membership/cluster.go
+++ b/etcdserver/api/membership/cluster.go
@@ -248,7 +248,8 @@ func (c *RaftCluster) Recover(onSet func(*zap.Logger, *semver.Version)) {
 
 	c.members, c.removed = membersFromStore(c.lg, c.v2store)
 	c.version = clusterVersionFromStore(c.lg, c.v2store)
-	mustDetectDowngrade(c.lg, c.version)
+	// TODO: add flag to control this check
+	//mustDetectDowngrade(c.lg, c.version)
 	onSet(c.lg, c.version)
 
 	for _, m := range c.members {
@@ -567,7 +568,8 @@ func (c *RaftCluster) SetVersion(ver *semver.Version, onSet func(*zap.Logger, *s
 	}
 	oldVer := c.version
 	c.version = ver
-	mustDetectDowngrade(c.lg, c.version)
+	// TODO: add flag to control this check
+	//mustDetectDowngrade(c.lg, c.version)
 	if c.v2store != nil {
 		mustSaveClusterVersionToStore(c.v2store, ver)
 	}
diff --git a/mvcc/kvstore.go b/mvcc/kvstore.go
index d688dcd1cfa..ab92605aca2 100644
--- a/mvcc/kvstore.go
+++ b/mvcc/kvstore.go
@@ -43,6 +43,10 @@ var (
 	scheduledCompactKeyName = []byte("scheduledCompactRev")
 	finishedCompactKeyName  = []byte("finishedCompactRev")
 
+	// 3.5 meta keys that have to be deleted for downgrade
+	confStateKeyName = []byte("confState")
+	termKeyName      = []byte("term")
+
 	ErrCompacted = errors.New("mvcc: required revision has been compacted")
 	ErrFutureRev = errors.New("mvcc: required revision is a future revision")
 	ErrCanceled  = errors.New("mvcc: watcher is canceled")
@@ -148,6 +152,8 @@ func NewStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentI
 	tx.Lock()
 	tx.UnsafeCreateBucket(keyBucketName)
 	tx.UnsafeCreateBucket(metaBucketName)
+	// TODO: add flag to control this
+	downgradeMetaBucket(tx)
 	tx.Unlock()
 	s.b.ForceCommit()
 
@@ -379,6 +385,9 @@ func (s *store) restore() error {
 	tx := s.b.BatchTx()
 	tx.Lock()
 
+	// TODO: add flag to control this
+	downgradeMetaBucket(tx)
+
 	_, finishedCompactBytes := tx.UnsafeRange(metaBucketName, finishedCompactKeyName, nil, 0)
 	if len(finishedCompactBytes) != 0 {
 		s.revMu.Lock()
@@ -637,3 +646,9 @@ func appendMarkTombstone(lg *zap.Logger, b []byte) []byte {
 func isTombstone(b []byte) bool {
 	return len(b) == markedRevBytesLen && b[markBytePosition] == markTombstone
 }
+
+// downgradeMetaBucket delete 3.5 specific keys to make backend fully compatible with 3.4
+func downgradeMetaBucket(tx backend.BatchTx) {
+	tx.UnsafeDelete(metaBucketName, confStateKeyName)
+	tx.UnsafeDelete(metaBucketName, termKeyName)
+}
diff --git a/mvcc/kvstore_test.go b/mvcc/kvstore_test.go
index 672878fa60c..0a763287746 100644
--- a/mvcc/kvstore_test.go
+++ b/mvcc/kvstore_test.go
@@ -397,6 +397,8 @@ func TestStoreRestore(t *testing.T) {
 		t.Errorf("current rev = %v, want 5", s.currentRev)
 	}
 	wact := []testutil.Action{
+		{Name: "delete", Params: []interface{}{metaBucketName, confStateKeyName}},
+		{Name: "delete", Params: []interface{}{metaBucketName, termKeyName}},
 		{Name: "range", Params: []interface{}{metaBucketName, finishedCompactKeyName, []byte(nil), int64(0)}},
 		{Name: "range", Params: []interface{}{metaBucketName, scheduledCompactKeyName, []byte(nil), int64(0)}},
 		{Name: "range", Params: []interface{}{keyBucketName, newTestRevBytes(revision{1, 0}), newTestRevBytes(revision{math.MaxInt64, math.MaxInt64}), int64(restoreChunkKeys)}},