diff --git a/commands.go b/commands.go
index 241923cef7..06443b559e 100644
--- a/commands.go
+++ b/commands.go
@@ -529,9 +529,6 @@ func (srv *Server) CmdPush(stdin io.ReadCloser, stdout rcli.DockerConn, args ...
 	Debugf("Pushing [%s] to [%s]\n", local, remote)
 
 	// Try to get the image
-	// FIXME: Handle lookup
-	// FIXME: Also push the tags in case of ./docker push myrepo:mytag
-	//	img, err := srv.runtime.LookupImage(cmd.Arg(0))
 	img, err := srv.runtime.graph.Get(local)
 	if err != nil {
 		Debugf("The push refers to a repository [%s] (len: %d)\n", local, len(srv.runtime.repositories.Repositories[local]))
diff --git a/graph.go b/graph.go
index d7a53be7c3..6e443f206b 100644
--- a/graph.go
+++ b/graph.go
@@ -81,13 +81,6 @@ func (graph *Graph) Get(name string) (*Image, error) {
 		return nil, fmt.Errorf("Image stored at '%s' has wrong id '%s'", id, img.Id)
 	}
 	img.graph = graph
-
-	if img.Checksum == "" {
-		err := img.FixChecksum()
-		if err != nil {
-			return nil, err
-		}
-	}
 	return img, nil
 }
 
@@ -105,17 +98,11 @@ func (graph *Graph) Create(layerData Archive, container *Container, comment, aut
 		img.Parent = container.Image
 		img.Container = container.Id
 		img.ContainerConfig = *container.Config
-		// FIXME: If an image is imported from a raw URL (not created from a container),
-		// its checksum will not be computed, which will cause a push to fail
-		checksum, err := container.RwChecksum()
-		if err != nil {
-			return nil, err
-		}
-		img.Checksum = checksum
 	}
 	if err := graph.Register(layerData, img); err != nil {
 		return nil, err
 	}
+	img.Checksum()
 	return img, nil
 }
 
@@ -309,7 +296,10 @@ func (graph *Graph) Checksums(repo Repository) ([]map[string]string, error) {
 			return nil, err
 		}
 		err = img.WalkHistory(func(image *Image) error {
-			checksums[image.Id] = image.Checksum
+			checksums[image.Id], err = image.Checksum()
+			if err != nil {
+				return err
+			}
 			return nil
 		})
 		if err != nil {
diff --git a/image.go b/image.go
index 4d625d6c0f..dcad130d3b 100644
--- a/image.go
+++ b/image.go
@@ -1,7 +1,9 @@
 package docker
 
 import (
+	"bytes"
 	"crypto/rand"
+	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
@@ -18,7 +20,6 @@ import (
 type Image struct {
 	Id              string    `json:"id"`
 	Parent          string    `json:"parent,omitempty"`
-	Checksum        string    `json:"checksum,omitempty"`
 	Comment         string    `json:"comment,omitempty"`
 	Created         time.Time `json:"created"`
 	Container       string    `json:"container,omitempty"`
@@ -260,30 +261,57 @@ func (img *Image) layer() (string, error) {
 	return layerPath(root), nil
 }
 
-func (img *Image) FixChecksum() error {
+func (img *Image) Checksum() (string, error) {
+	root, err := img.root()
+	if err != nil {
+		return "", err
+	}
+
+	checksumDictPth := path.Join(root, "..", "..", "checksums")
+	checksums := new(map[string]string)
+
+	if checksumDict, err := ioutil.ReadFile(checksumDictPth); err == nil {
+		if err := json.Unmarshal(checksumDict, checksums); err != nil {
+			return "", err
+		}
+		if checksum, ok := (*checksums)[img.Id]; ok {
+			return checksum, nil
+		}
+	}
+
 	layer, err := img.layer()
 	if err != nil {
-		return err
+		return "", err
 	}
 	layerData, err := Tar(layer, Xz)
 	if err != nil {
-		return err
+		return "", err
 	}
-	sum, err := HashData(layerData)
+	h := sha256.New()
+	if _, err := io.Copy(h, layerData); err != nil {
+		return "", err
+	}
+
+	jsonData, err := ioutil.ReadFile(jsonPath(root))
 	if err != nil {
-		return err
+		return "", err
 	}
-	img.Checksum = sum
-	jsonData, err := json.Marshal(img)
+	if _, err := io.Copy(h, bytes.NewBuffer(jsonData)); err != nil {
+		return "", err
+	}
+
+	hash := "sha256:"+hex.EncodeToString(h.Sum(nil))
+	if *checksums == nil {
+		*checksums = map[string]string{}
+	}
+	(*checksums)[img.Id] = hash
+	checksumJson, err := json.Marshal(checksums)
 	if err != nil {
-		return err
+		return hash, err
 	}
-	root, err := img.root()
-	if err != nil {
-		return err
+
+	if err := ioutil.WriteFile(checksumDictPth, checksumJson, 0600); err != nil {
+		return hash, err
 	}
-	if err := ioutil.WriteFile(jsonPath(root), jsonData, 0600); err != nil {
-		return err
-	}
-	return nil
+	return hash, nil
 }
diff --git a/registry.go b/registry.go
index 5da811b123..be9d37edc1 100644
--- a/registry.go
+++ b/registry.go
@@ -327,6 +327,12 @@ func pushImageRec(graph *Graph, stdout io.Writer, img *Image, registry string, t
 	}
 	req.Header.Add("Content-type", "application/json")
 	req.Header.Set("Authorization", "Token " + strings.Join(token, ","))
+
+	checksum, err := img.Checksum()
+	if err != nil {
+		return fmt.Errorf("Error while retrieving checksum for %s: %v", img.Id, err)
+	}
+	req.Header.Set("X-Docker-Checksum", checksum)
 	res, err := doWithCookies(client, req)
 	if err != nil {
 		return fmt.Errorf("Failed to upload metadata: %s", err)
@@ -457,7 +463,7 @@ func (graph *Graph) PushRepository(stdout io.Writer, remote string, localRepo Re
 		return err
 	}
 
-	req, err := http.NewRequest("PUT", INDEX_ENDPOINT+"/repositories/"+remote, bytes.NewReader(imgListJson))
+	req, err := http.NewRequest("PUT", INDEX_ENDPOINT+"/repositories/"+remote+"/", bytes.NewReader(imgListJson))
 	if err != nil {
 		return err
 	}
@@ -468,7 +474,7 @@ func (graph *Graph) PushRepository(stdout io.Writer, remote string, localRepo Re
 	if err != nil {
 		return err
 	}
-	res.Body.Close()
+	defer res.Body.Close()
 	for res.StatusCode >= 300 && res.StatusCode < 400 {
 		Debugf("Redirected to %s\n", res.Header.Get("Location"))
 		req, err = http.NewRequest("PUT", res.Header.Get("Location"), bytes.NewReader(imgListJson))
@@ -482,10 +488,12 @@ func (graph *Graph) PushRepository(stdout io.Writer, remote string, localRepo Re
 		if err != nil {
 			return err
 		}
-		res.Body.Close()
+		defer res.Body.Close()
 	}
 
 	if res.StatusCode != 200 && res.StatusCode != 201 {
+		info, err := ioutil.ReadAll(res.Body)
+		Debugf("%v %v", err, string(info))
 		return fmt.Errorf("Error: Status %d trying to push repository %s", res.StatusCode, remote)
 	}