diff --git a/api/api_full.go b/api/api_full.go
index 6d2d0c7b5..0e5622f4c 100644
--- a/api/api_full.go
+++ b/api/api_full.go
@@ -176,6 +176,9 @@ type FullNode interface {
 	// the reason.
 	SyncCheckBad(ctx context.Context, bcid cid.Cid) (string, error)
 
+	// SyncValidateTipset indicates whether the provided tipset is valid or not
+	SyncValidateTipset(ctx context.Context, tsk types.TipSetKey) (bool, error)
+
 	// MethodGroup: Mpool
 	// The Mpool methods are for interacting with the message pool. The message pool
 	// manages all incoming and outgoing 'messages' going over the network.
diff --git a/api/apistruct/struct.go b/api/apistruct/struct.go
index d5b6950ad..cc2b8b5b5 100644
--- a/api/apistruct/struct.go
+++ b/api/apistruct/struct.go
@@ -112,6 +112,7 @@ type FullNodeStruct struct {
 		SyncMarkBad        func(ctx context.Context, bcid cid.Cid) error                `perm:"admin"`
 		SyncUnmarkBad      func(ctx context.Context, bcid cid.Cid) error                `perm:"admin"`
 		SyncCheckBad       func(ctx context.Context, bcid cid.Cid) (string, error)      `perm:"read"`
+		SyncValidateTipset func(ctx context.Context, tsk types.TipSetKey) (bool, error) `perm:"read"`
 
 		MpoolGetConfig func(context.Context) (*types.MpoolConfig, error) `perm:"read"`
 		MpoolSetConfig func(context.Context, *types.MpoolConfig) error   `perm:"write"`
@@ -735,6 +736,10 @@ func (c *FullNodeStruct) SyncCheckBad(ctx context.Context, bcid cid.Cid) (string
 	return c.Internal.SyncCheckBad(ctx, bcid)
 }
 
+func (c *FullNodeStruct) SyncValidateTipset(ctx context.Context, tsk types.TipSetKey) (bool, error) {
+	return c.Internal.SyncValidateTipset(ctx, tsk)
+}
+
 func (c *FullNodeStruct) StateNetworkName(ctx context.Context) (dtypes.NetworkName, error) {
 	return c.Internal.StateNetworkName(ctx)
 }
diff --git a/chain/store/store.go b/chain/store/store.go
index 6c93db7a0..0806fb921 100644
--- a/chain/store/store.go
+++ b/chain/store/store.go
@@ -286,6 +286,16 @@ func (cs *ChainStore) MarkBlockAsValidated(ctx context.Context, blkid cid.Cid) e
 	return nil
 }
 
+func (cs *ChainStore) UnmarkBlockAsValidated(ctx context.Context, blkid cid.Cid) error {
+	key := blockValidationCacheKeyPrefix.Instance(blkid.String())
+
+	if err := cs.ds.Delete(key); err != nil {
+		return xerrors.Errorf("removing from valid block cache: %w", err)
+	}
+
+	return nil
+}
+
 func (cs *ChainStore) SetGenesis(b *types.BlockHeader) error {
 	ts, err := types.NewTipSet([]*types.BlockHeader{b})
 	if err != nil {
diff --git a/cmd/lotus-shed/main.go b/cmd/lotus-shed/main.go
index c7ded7a25..3864d3014 100644
--- a/cmd/lotus-shed/main.go
+++ b/cmd/lotus-shed/main.go
@@ -38,6 +38,7 @@ func main() {
 		exportChainCmd,
 		consensusCmd,
 		serveDealStatsCmd,
+		syncCmd,
 	}
 
 	app := &cli.App{
diff --git a/cmd/lotus-shed/sync.go b/cmd/lotus-shed/sync.go
new file mode 100644
index 000000000..bfe7cc8b7
--- /dev/null
+++ b/cmd/lotus-shed/sync.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/ipfs/go-cid"
+
+	"github.com/filecoin-project/lotus/chain/types"
+	lcli "github.com/filecoin-project/lotus/cli"
+	"github.com/urfave/cli/v2"
+)
+
+var syncCmd = &cli.Command{
+	Name:  "sync",
+	Usage: "tools for diagnosing sync issues",
+	Flags: []cli.Flag{},
+	Subcommands: []*cli.Command{
+		syncValidateCmd,
+	},
+}
+
+var syncValidateCmd = &cli.Command{
+	Name:  "validate",
+	Usage: "checks whether a provided tipset is valid",
+	Action: func(cctx *cli.Context) error {
+		api, closer, err := lcli.GetFullNodeAPI(cctx)
+		if err != nil {
+			return err
+		}
+
+		defer closer()
+		ctx := lcli.ReqContext(cctx)
+
+		if cctx.Args().Len() < 1 {
+			fmt.Println("usage: <blockCid1> <blockCid2>...")
+			fmt.Println("At least one block cid must be provided")
+			return nil
+		}
+
+		args := cctx.Args().Slice()
+
+		var tscids []cid.Cid
+		for _, s := range args {
+			c, err := cid.Decode(s)
+			if err != nil {
+				return fmt.Errorf("block cid was invalid: %s", err)
+			}
+			tscids = append(tscids, c)
+		}
+
+		tsk := types.NewTipSetKey(tscids...)
+
+		valid, err := api.SyncValidateTipset(ctx, tsk)
+		if err != nil {
+			fmt.Println("Tipset is invalid: ", err)
+		}
+
+		if valid {
+			fmt.Println("Tipset is valid")
+		}
+
+		return nil
+	},
+}
diff --git a/node/impl/full/sync.go b/node/impl/full/sync.go
index dc3bfe230..221942673 100644
--- a/node/impl/full/sync.go
+++ b/node/impl/full/sync.go
@@ -126,3 +126,29 @@ func (a *SyncAPI) SyncCheckBad(ctx context.Context, bcid cid.Cid) (string, error
 
 	return reason, nil
 }
+
+func (a *SyncAPI) SyncValidateTipset(ctx context.Context, tsk types.TipSetKey) (bool, error) {
+	ts, err := a.Syncer.ChainStore().LoadTipSet(tsk)
+	if err != nil {
+		return false, err
+	}
+
+	fts, err := a.Syncer.ChainStore().TryFillTipSet(ts)
+	if err != nil {
+		return false, err
+	}
+
+	for _, blk := range tsk.Cids() {
+		err = a.Syncer.ChainStore().UnmarkBlockAsValidated(ctx, blk)
+		if err != nil {
+			return false, err
+		}
+	}
+
+	err = a.Syncer.ValidateTipSet(ctx, fts)
+	if err != nil {
+		return false, err
+	}
+
+	return true, nil
+}