diff --git a/chunk/replicator.go b/chunk/replicator.go
index 5fcabc7..f7f19ea 100644
--- a/chunk/replicator.go
+++ b/chunk/replicator.go
@@ -9,28 +9,22 @@
 	"github.com/giolekva/pcloud/api"
 )
 
+type ReplicaAssignmentChangeListener interface {
+	Primary(chunkId, currentPrimary string) <-chan string
+}
+
 type PrimaryReplicaChangeListener interface {
 	ChunkId() string
 	Address() <-chan string
 }
 
-type NonChangingPrimaryReplicaChangeListener struct {
-	chunkId string
-	ch      chan string
+type NonChangingReplicaAssignment struct {
 }
 
-func NewNonChangingPrimaryReplicaChangeListener(chunkId, address string) PrimaryReplicaChangeListener {
+func (l *NonChangingReplicaAssignment) Primary(chunkId, address string) <-chan string {
 	ch := make(chan string, 1)
 	ch <- address
-	return &NonChangingPrimaryReplicaChangeListener{chunkId, ch}
-}
-
-func (l NonChangingPrimaryReplicaChangeListener) ChunkId() string {
-	return l.chunkId
-}
-
-func (l NonChangingPrimaryReplicaChangeListener) Address() <-chan string {
-	return l.ch
+	return ch
 }
 
 func replicate(ctx context.Context, dst, src Chunk, done chan<- int) {
@@ -61,7 +55,7 @@
 	}
 }
 
-func ReplicateFromPrimary(ctx context.Context, dst Chunk, l PrimaryReplicaChangeListener) {
+func ReplicateFromPrimary(ctx context.Context, chunkId string, dst Chunk, primaryAddressCh <-chan string) {
 	var done chan int
 	var cancel context.CancelFunc = nil
 	for {
@@ -70,7 +64,7 @@
 			return
 		case <-ctx.Done():
 			return
-		case address := <-l.Address():
+		case address := <-primaryAddressCh:
 			if cancel != nil {
 				cancel()
 			}
@@ -82,7 +76,7 @@
 				continue
 			}
 			client := api.NewChunkStorageClient(conn)
-			src := RemoteChunk{l.ChunkId(), client}
+			src := RemoteChunk{chunkId, client}
 			replicatorCtx, cancelFn := context.WithCancel(context.Background())
 			cancel = cancelFn
 			done = make(chan int, 1)
@@ -91,7 +85,7 @@
 	}
 }
 
-func WriteToPrimary(ctx context.Context, src Chunk, l PrimaryReplicaChangeListener) {
+func WriteToPrimary(ctx context.Context, chunkId string, src Chunk, primaryAddressCh <-chan string) {
 	var done chan int
 	var cancel context.CancelFunc = nil
 	for {
@@ -100,7 +94,7 @@
 			return
 		case <-ctx.Done():
 			return
-		case address := <-l.Address():
+		case address := <-primaryAddressCh:
 			if cancel != nil {
 				cancel()
 			}
@@ -112,7 +106,7 @@
 				continue
 			}
 			client := api.NewChunkStorageClient(conn)
-			dst := RemoteChunk{l.ChunkId(), client}
+			dst := RemoteChunk{chunkId, client}
 			replicatorCtx, cancelFn := context.WithCancel(context.Background())
 			cancel = cancelFn
 			done = make(chan int, 1)
diff --git a/chunk/server.go b/chunk/server.go
index c262509..7f07227 100644
--- a/chunk/server.go
+++ b/chunk/server.go
@@ -11,13 +11,17 @@
 )
 
 type ChunkServer struct {
-	factory          ChunkFactory
-	chunks           sync.Map
-	replicatorCancel sync.Map
+	factory             ChunkFactory
+	assignmentChangeLis ReplicaAssignmentChangeListener
+	chunks              sync.Map
+	replicatorCancel    sync.Map
 }
 
-func NewChunkServer(factory ChunkFactory) *ChunkServer {
-	return &ChunkServer{factory: factory}
+func NewChunkServer(factory ChunkFactory,
+	assignmentChangeLis ReplicaAssignmentChangeListener) *ChunkServer {
+	return &ChunkServer{
+		factory:             factory,
+		assignmentChangeLis: assignmentChangeLis}
 }
 
 func (s *ChunkServer) ListChunks(
@@ -40,10 +44,9 @@
 	case api.ReplicaRole_SECONDARY:
 		ctx, cancel := context.WithCancel(context.Background())
 		s.replicatorCancel.Store(req.ChunkId, cancel)
-		primaryListener := NewNonChangingPrimaryReplicaChangeListener(
-			req.ChunkId,
-			req.PrimaryAddress)
-		go ReplicateFromPrimary(ctx, chunk, primaryListener)
+		primaryAddressCh := s.assignmentChangeLis.Primary(
+			req.ChunkId, req.PrimaryAddress)
+		go ReplicateFromPrimary(ctx, req.ChunkId, chunk, primaryAddressCh)
 	case api.ReplicaRole_PRIMARY:
 		{
 		}
diff --git a/chunk.go b/chunk_server.go
similarity index 89%
rename from chunk.go
rename to chunk_server.go
index d8e9f21..8238a73 100644
--- a/chunk.go
+++ b/chunk_server.go
@@ -48,6 +48,8 @@
 		log.Fatalf("failed to listen: %v", err)
 	}
 	server := grpc.NewServer()
-	api.RegisterChunkStorageServer(server, chunk.NewChunkServer())
+	api.RegisterChunkStorageServer(server, chunk.NewChunkServer(
+		&chunk.InMemoryChunkFactory{},
+		&chunk.NonChangingReplicaAssignment{}))
 	server.Serve(lis)
 }
diff --git a/client/client.go b/client/client.go
index 99c30fa..974c3e8 100644
--- a/client/client.go
+++ b/client/client.go
@@ -31,11 +31,13 @@
 	if len(resp.Chunk) != 1 {
 		panic(resp)
 	}
-	primaryListener := chunk.NewNonChangingPrimaryReplicaChangeListener(
+	lis := &chunk.NonChangingReplicaAssignment{}
+	primaryAddressCh := lis.Primary(
 		resp.Chunk[0].ChunkId,
 		resp.Chunk[0].Server[0])
 	chunk.WriteToPrimary(
 		context.Background(),
+		resp.Chunk[0].ChunkId,
 		chunk.NewReadOnlyFileChunk(f, 0, int(info.Size())),
-		primaryListener)
+		primaryAddressCh)
 }
diff --git a/testing/in_memory_env.go b/testing/in_memory_env.go
index ff6485f..e2aace3 100644
--- a/testing/in_memory_env.go
+++ b/testing/in_memory_env.go
@@ -50,7 +50,9 @@
 			return nil, err
 		}
 		server := grpc.NewServer()
-		api.RegisterChunkStorageServer(server, chunk.NewChunkServer(&chunk.InMemoryChunkFactory{}))
+		api.RegisterChunkStorageServer(server, chunk.NewChunkServer(
+			&chunk.InMemoryChunkFactory{},
+			&chunk.NonChangingReplicaAssignment{}))
 		go server.Serve(lis)
 		env.c[i] = server
 	}