diff --git a/chaindata/mainnet/chain_test.go b/chaindata/mainnet/chain_test.go
new file mode 100644
index 0000000..94ec8b1
--- /dev/null
+++ b/chaindata/mainnet/chain_test.go
@@ -0,0 +1,23 @@
+package mainnet_test
+
+import (
+	"testing"
+
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/vm"
+
+	"github.com/cerc-io/eth-testing/chaindata/mainnet"
+)
+
+func TestLoadChain(t *testing.T) {
+	db := rawdb.NewMemoryDatabase()
+	core.DefaultGenesisBlock().MustCommit(db)
+	blocks := mainnet.GetBlocks()
+	chain, _ := core.NewBlockChain(db, nil, nil, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	_, err := chain.InsertChain(blocks[1:])
+	if err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/chaindata/util/chaindata_test.go b/chaindata/util/chaindata_test.go
new file mode 100644
index 0000000..7f56957
--- /dev/null
+++ b/chaindata/util/chaindata_test.go
@@ -0,0 +1,42 @@
+package util_test
+
+import (
+	"testing"
+
+	"github.com/ethereum/go-ethereum/core/rawdb"
+
+	"github.com/cerc-io/eth-testing/chaindata/util"
+)
+
+func testReadChainData(t *testing.T, name string) {
+	ChainDataPath, AncientDataPath := util.ChainDataPaths(name)
+
+	kvdb, ldberr := rawdb.NewLevelDBDatabase(ChainDataPath, 1024, 256, "vdb-geth", false)
+	if ldberr != nil {
+		t.Fatal(ldberr)
+	}
+	edb, err := rawdb.NewDatabaseWithFreezer(kvdb, AncientDataPath, "vdb-geth", false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer edb.Close()
+
+	hash := rawdb.ReadHeadHeaderHash(edb)
+	height := rawdb.ReadHeaderNumber(edb, hash)
+	if height == nil {
+		t.Fatalf("unable to read header height for header hash %s", hash)
+	}
+	header := rawdb.ReadHeader(edb, hash, *height)
+	if header == nil {
+		t.Fatalf("unable to read canonical header at height %d", height)
+	}
+}
+
+func TestReadChainData(t *testing.T) {
+	for _, name := range []string{"small", "medium"} {
+		t.Run(name, func(t *testing.T) { testReadChainData(t, name) })
+	}
+}
diff --git a/go.mod b/go.mod
index 349b67d..eb61478 100644
--- a/go.mod
+++ b/go.mod
@@ -17,6 +17,7 @@ require (
 	github.com/cockroachdb/redact v1.1.3 // indirect
 	github.com/deckarep/golang-set/v2 v2.1.0 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	github.com/edsrzf/mmap-go v1.0.0 // indirect
 	github.com/getsentry/sentry-go v0.18.0 // indirect
 	github.com/go-ole/go-ole v1.2.1 // indirect
 	github.com/go-stack/stack v1.8.1 // indirect
diff --git a/go.sum b/go.sum
index 3d93c2e..77bea1a 100644
--- a/go.sum
+++ b/go.sum
@@ -57,6 +57,7 @@ github.com/dgraph-io/badger v1.6.0/go.mod h1:zwt7syl517jmP8s94KqSxTlM6IMsdhYy6ps
 github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/edsrzf/mmap-go v1.0.0 h1:CEBF7HpRnUCSJgGUb5h1Gm7e3VkmVDrR8lvWVLtrOFw=
+github.com/edsrzf/mmap-go v1.0.0/go.mod h1:YO35OhQPt3KJa3ryjFM5Bs14WD66h8eGKpfaBNrHW5M=
 github.com/eknkc/amber v0.0.0-20171010120322-cdade1c07385/go.mod h1:0vRUJqYpeSZifjYj7uP3BG/gKcuzL9xWVV/Y+cK33KM=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=