diff --git a/common/block.go b/common/block.go
index 36e2b0b..266ce3c 100644
--- a/common/block.go
+++ b/common/block.go
@@ -1,7 +1,31 @@
 package common
 
-// Block data from Minetest database.
-type Block struct {
-	Coord Coord
-	Data  []byte
-}
+import (
+	"errors"
+)
+
+// Error returned if a Producer has run to its end.
+var ErrNoMoreBlocks = errors.New("No more blocks.")
+
+type (
+	// Block data from Minetest database.
+	Block struct {
+		Coord 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
+		// Closes the open database connections.
+		Close() error
+	}
+
+	// BlockConsumer is used to store blocks in a new Minetest database.
+	BlockConsumer interface {
+		Consume(*Block) error
+		// Closes the open database connections.
+		Close() error
+	}
+)
diff --git a/interleaver/interfaces.go b/interleaver/interfaces.go
deleted file mode 100644
index 063668f..0000000
--- a/interleaver/interfaces.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2014 by Sascha L. Teichmann
-// Use of this source code is governed by the MIT license
-// that can be found in the LICENSE file.
-
-package main
-
-import (
-	"errors"
-
-	"bitbucket.org/s_l_teichmann/mtredisalize/common"
-)
-
-// Error returned if a Producer has run to its end.
-var ErrNoMoreBlocks = errors.New("No more blocks.")
-
-type (
-	// 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(*common.Block) error
-		// Closes the open database connections.
-		Close() error
-	}
-
-	// BlockConsumer is used to store blocks in a new Minetest database.
-	BlockConsumer interface {
-		Consume(*common.Block) error
-		// Closes the open database connections.
-		Close() error
-	}
-)
diff --git a/interleaver/leveldb.go b/interleaver/leveldb.go
index 82a7e06..5ade27d 100644
--- a/interleaver/leveldb.go
+++ b/interleaver/leveldb.go
@@ -77,12 +77,12 @@ func (ldbp *LevelDBBlockProducer) Close() error {
 
 func (ldbp *LevelDBBlockProducer) Next(block *common.Block) (err error) {
 	if ldbp.iterator == nil {
-		err = ErrNoMoreBlocks
+		err = common.ErrNoMoreBlocks
 		return
 	}
 	if !ldbp.iterator.Valid() {
 		if err = ldbp.iterator.GetError(); err == nil {
-			err = ErrNoMoreBlocks
+			err = common.ErrNoMoreBlocks
 		}
 		ldbp.iterator.Close()
 		ldbp.iterator = nil
diff --git a/interleaver/main.go b/interleaver/main.go
index f1e940b..e099103 100644
--- a/interleaver/main.go
+++ b/interleaver/main.go
@@ -49,7 +49,7 @@ func selectKeyEncoder(interleaved bool) common.KeyEncoder {
 	return common.EncodeStringToBytes
 }
 
-func copyProducerToConsumer(producer BlockProducer, consumer BlockConsumer) error {
+func copyProducerToConsumer(producer common.BlockProducer, consumer common.BlockConsumer) error {
 
 	blocks := make(chan *common.Block)
 	done := make(chan struct{})
@@ -62,7 +62,7 @@ func copyProducerToConsumer(producer BlockProducer, consumer BlockConsumer) erro
 		for {
 			block := pool.Get().(*common.Block)
 			if err := producer.Next(block); err != nil {
-				if err != ErrNoMoreBlocks {
+				if err != common.ErrNoMoreBlocks {
 					log.Printf("Reading failed: %s\n", err)
 				}
 				return
@@ -126,8 +126,8 @@ func main() {
 	}
 
 	var (
-		producer BlockProducer
-		consumer BlockConsumer
+		producer common.BlockProducer
+		consumer common.BlockConsumer
 		err      error
 	)
 
diff --git a/interleaver/sqlite.go b/interleaver/sqlite.go
index 068d5cb..817c7be 100644
--- a/interleaver/sqlite.go
+++ b/interleaver/sqlite.go
@@ -151,7 +151,7 @@ func NewSQLiteBlockProducer(
 
 func (sbp *SQLiteBlockProducer) Next(block *common.Block) (err error) {
 	if sbp.rows == nil {
-		err = ErrNoMoreBlocks
+		err = common.ErrNoMoreBlocks
 		return
 	}
 	if sbp.rows.Next() {
@@ -162,7 +162,7 @@ func (sbp *SQLiteBlockProducer) Next(block *common.Block) (err error) {
 	} else {
 		sbp.rows.Close()
 		sbp.rows = nil
-		err = ErrNoMoreBlocks
+		err = common.ErrNoMoreBlocks
 	}
 	return
 }