diff --git a/common/block.go b/common/block.go
new file mode 100644
index 0000000..36e2b0b
--- /dev/null
+++ b/common/block.go
@@ -0,0 +1,7 @@
+package common
+
+// Block data from Minetest database.
+type Block struct {
+	Coord Coord
+	Data  []byte
+}
diff --git a/interleaver/interfaces.go b/interleaver/interfaces.go
index 444122c..063668f 100644
--- a/interleaver/interfaces.go
+++ b/interleaver/interfaces.go
@@ -14,24 +14,18 @@ import (
 var ErrNoMoreBlocks = errors.New("No more blocks.")
 
 type (
-	// Block data from Minetest database.
-	Block struct {
-		Coord common.Coord
-		Data  []byte
-	}
-
 	// BlockProducer is used to over a existing Minetest database
 	// and return its content block by block.
 	BlockProducer interface {
 		// error is ErrNoMoreBlocks if it run out of blocks.
-		Next(*Block) error
+		Next(*common.Block) error
 		// Closes the open database connections.
 		Close() error
 	}
 
 	// BlockConsumer is used to store blocks in a new Minetest database.
 	BlockConsumer interface {
-		Consume(*Block) error
+		Consume(*common.Block) error
 		// Closes the open database connections.
 		Close() error
 	}
diff --git a/interleaver/leveldb.go b/interleaver/leveldb.go
index 6474b5b..82a7e06 100644
--- a/interleaver/leveldb.go
+++ b/interleaver/leveldb.go
@@ -75,7 +75,7 @@ func (ldbp *LevelDBBlockProducer) Close() error {
 	return nil
 }
 
-func (ldbp *LevelDBBlockProducer) Next(block *Block) (err error) {
+func (ldbp *LevelDBBlockProducer) Next(block *common.Block) (err error) {
 	if ldbp.iterator == nil {
 		err = ErrNoMoreBlocks
 		return
@@ -127,7 +127,7 @@ func (ldbc *LevelDBBlockConsumer) Close() error {
 	return nil
 }
 
-func (ldbc *LevelDBBlockConsumer) Consume(block *Block) (err error) {
+func (ldbc *LevelDBBlockConsumer) Consume(block *common.Block) (err error) {
 	var encodedKey []byte
 	if encodedKey, err = ldbc.encoder(ldbc.joiner(block.Coord)); err != nil {
 		return
diff --git a/interleaver/main.go b/interleaver/main.go
index 5af72c4..f1e940b 100644
--- a/interleaver/main.go
+++ b/interleaver/main.go
@@ -51,16 +51,16 @@ func selectKeyEncoder(interleaved bool) common.KeyEncoder {
 
 func copyProducerToConsumer(producer BlockProducer, consumer BlockConsumer) error {
 
-	blocks := make(chan *Block)
+	blocks := make(chan *common.Block)
 	done := make(chan struct{})
 	defer close(done)
 
-	pool := sync.Pool{New: func() interface{} { return new(Block) }}
+	pool := sync.Pool{New: func() interface{} { return new(common.Block) }}
 
 	go func() {
 		defer close(blocks)
 		for {
-			block := pool.Get().(*Block)
+			block := pool.Get().(*common.Block)
 			if err := producer.Next(block); err != nil {
 				if err != ErrNoMoreBlocks {
 					log.Printf("Reading failed: %s\n", err)
diff --git a/interleaver/sqlite.go b/interleaver/sqlite.go
index e1789b8..068d5cb 100644
--- a/interleaver/sqlite.go
+++ b/interleaver/sqlite.go
@@ -112,7 +112,7 @@ func (sbc *SQLiteBlockConsumer) getTx() (tx *sql.Tx, err error) {
 	return
 }
 
-func (sbc *SQLiteBlockConsumer) Consume(block *Block) (err error) {
+func (sbc *SQLiteBlockConsumer) Consume(block *common.Block) (err error) {
 	var tx *sql.Tx
 	if tx, err = sbc.getTx(); err != nil {
 		return
@@ -149,7 +149,7 @@ func NewSQLiteBlockProducer(
 	return
 }
 
-func (sbp *SQLiteBlockProducer) Next(block *Block) (err error) {
+func (sbp *SQLiteBlockProducer) Next(block *common.Block) (err error) {
 	if sbp.rows == nil {
 		err = ErrNoMoreBlocks
 		return