diff --git a/daemon/commit.go b/daemon/commit.go
index 8865d832f3..6af494da74 100644
--- a/daemon/commit.go
+++ b/daemon/commit.go
@@ -1,9 +1,7 @@
 package daemon // import "github.com/docker/docker/daemon"
 
 import (
-	"encoding/json"
 	"fmt"
-	"io"
 	"runtime"
 	"strings"
 	"time"
@@ -12,10 +10,6 @@ import (
 	containertypes "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/builder/dockerfile"
 	"github.com/docker/docker/errdefs"
-	"github.com/docker/docker/image"
-	"github.com/docker/docker/layer"
-	"github.com/docker/docker/pkg/ioutils"
-	"github.com/docker/docker/pkg/system"
 	"github.com/pkg/errors"
 )
 
@@ -190,115 +184,3 @@ func (daemon *Daemon) CreateImageFromContainer(name string, c *backend.CreateIma
 	containerActions.WithValues("commit").UpdateSince(start)
 	return id.String(), nil
 }
-
-func (daemon *Daemon) commitImage(c backend.CommitConfig) (image.ID, error) {
-	layerStore, ok := daemon.layerStores[c.ContainerOS]
-	if !ok {
-		return "", system.ErrNotSupportedOperatingSystem
-	}
-	rwTar, err := exportContainerRw(layerStore, c.ContainerID, c.ContainerMountLabel)
-	if err != nil {
-		return "", err
-	}
-	defer func() {
-		if rwTar != nil {
-			rwTar.Close()
-		}
-	}()
-
-	var parent *image.Image
-	if c.ParentImageID == "" {
-		parent = new(image.Image)
-		parent.RootFS = image.NewRootFS()
-	} else {
-		parent, err = daemon.imageStore.Get(image.ID(c.ParentImageID))
-		if err != nil {
-			return "", err
-		}
-	}
-
-	l, err := layerStore.Register(rwTar, parent.RootFS.ChainID())
-	if err != nil {
-		return "", err
-	}
-	defer layer.ReleaseAndLog(layerStore, l)
-
-	cc := image.ChildConfig{
-		ContainerID:     c.ContainerID,
-		Author:          c.Author,
-		Comment:         c.Comment,
-		ContainerConfig: c.ContainerConfig,
-		Config:          c.Config,
-		DiffID:          l.DiffID(),
-	}
-	config, err := json.Marshal(image.NewChildImage(parent, cc, c.ContainerOS))
-	if err != nil {
-		return "", err
-	}
-
-	id, err := daemon.imageStore.Create(config)
-	if err != nil {
-		return "", err
-	}
-
-	if c.ParentImageID != "" {
-		if err := daemon.imageStore.SetParent(id, image.ID(c.ParentImageID)); err != nil {
-			return "", err
-		}
-	}
-	return id, nil
-}
-
-func exportContainerRw(layerStore layer.Store, id, mountLabel string) (arch io.ReadCloser, err error) {
-	rwlayer, err := layerStore.GetRWLayer(id)
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		if err != nil {
-			layerStore.ReleaseRWLayer(rwlayer)
-		}
-	}()
-
-	// TODO: this mount call is not necessary as we assume that TarStream() should
-	// mount the layer if needed. But the Diff() function for windows requests that
-	// the layer should be mounted when calling it. So we reserve this mount call
-	// until windows driver can implement Diff() interface correctly.
-	_, err = rwlayer.Mount(mountLabel)
-	if err != nil {
-		return nil, err
-	}
-
-	archive, err := rwlayer.TarStream()
-	if err != nil {
-		rwlayer.Unmount()
-		return nil, err
-	}
-	return ioutils.NewReadCloserWrapper(archive, func() error {
-			archive.Close()
-			err = rwlayer.Unmount()
-			layerStore.ReleaseRWLayer(rwlayer)
-			return err
-		}),
-		nil
-}
-
-// CommitBuildStep is used by the builder to create an image for each step in
-// the build.
-//
-// This method is different from CreateImageFromContainer:
-//   * it doesn't attempt to validate container state
-//   * it doesn't send a commit action to metrics
-//   * it doesn't log a container commit event
-//
-// This is a temporary shim. Should be removed when builder stops using commit.
-func (daemon *Daemon) CommitBuildStep(c backend.CommitConfig) (image.ID, error) {
-	container, err := daemon.GetContainer(c.ContainerID)
-	if err != nil {
-		return "", err
-	}
-	c.ContainerMountLabel = container.MountLabel
-	c.ContainerOS = container.OS
-	c.ParentImageID = string(container.ImageID)
-	return daemon.commitImage(c)
-}
diff --git a/daemon/image_commit.go b/daemon/image_commit.go
new file mode 100644
index 0000000000..48f890b80d
--- /dev/null
+++ b/daemon/image_commit.go
@@ -0,0 +1,124 @@
+package daemon // import "github.com/docker/docker/daemon"
+
+import (
+	"encoding/json"
+	"io"
+
+	"github.com/docker/docker/api/types/backend"
+	"github.com/docker/docker/image"
+	"github.com/docker/docker/layer"
+	"github.com/docker/docker/pkg/ioutils"
+	"github.com/docker/docker/pkg/system"
+)
+
+func (daemon *Daemon) commitImage(c backend.CommitConfig) (image.ID, error) {
+	layerStore, ok := daemon.layerStores[c.ContainerOS]
+	if !ok {
+		return "", system.ErrNotSupportedOperatingSystem
+	}
+	rwTar, err := exportContainerRw(layerStore, c.ContainerID, c.ContainerMountLabel)
+	if err != nil {
+		return "", err
+	}
+	defer func() {
+		if rwTar != nil {
+			rwTar.Close()
+		}
+	}()
+
+	var parent *image.Image
+	if c.ParentImageID == "" {
+		parent = new(image.Image)
+		parent.RootFS = image.NewRootFS()
+	} else {
+		parent, err = daemon.imageStore.Get(image.ID(c.ParentImageID))
+		if err != nil {
+			return "", err
+		}
+	}
+
+	l, err := layerStore.Register(rwTar, parent.RootFS.ChainID())
+	if err != nil {
+		return "", err
+	}
+	defer layer.ReleaseAndLog(layerStore, l)
+
+	cc := image.ChildConfig{
+		ContainerID:     c.ContainerID,
+		Author:          c.Author,
+		Comment:         c.Comment,
+		ContainerConfig: c.ContainerConfig,
+		Config:          c.Config,
+		DiffID:          l.DiffID(),
+	}
+	config, err := json.Marshal(image.NewChildImage(parent, cc, c.ContainerOS))
+	if err != nil {
+		return "", err
+	}
+
+	id, err := daemon.imageStore.Create(config)
+	if err != nil {
+		return "", err
+	}
+
+	if c.ParentImageID != "" {
+		if err := daemon.imageStore.SetParent(id, image.ID(c.ParentImageID)); err != nil {
+			return "", err
+		}
+	}
+	return id, nil
+}
+
+func exportContainerRw(layerStore layer.Store, id, mountLabel string) (arch io.ReadCloser, err error) {
+	rwlayer, err := layerStore.GetRWLayer(id)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			layerStore.ReleaseRWLayer(rwlayer)
+		}
+	}()
+
+	// TODO: this mount call is not necessary as we assume that TarStream() should
+	// mount the layer if needed. But the Diff() function for windows requests that
+	// the layer should be mounted when calling it. So we reserve this mount call
+	// until windows driver can implement Diff() interface correctly.
+	_, err = rwlayer.Mount(mountLabel)
+	if err != nil {
+		return nil, err
+	}
+
+	archive, err := rwlayer.TarStream()
+	if err != nil {
+		rwlayer.Unmount()
+		return nil, err
+	}
+	return ioutils.NewReadCloserWrapper(archive, func() error {
+			archive.Close()
+			err = rwlayer.Unmount()
+			layerStore.ReleaseRWLayer(rwlayer)
+			return err
+		}),
+		nil
+}
+
+// CommitBuildStep is used by the builder to create an image for each step in
+// the build.
+//
+// This method is different from CreateImageFromContainer:
+//   * it doesn't attempt to validate container state
+//   * it doesn't send a commit action to metrics
+//   * it doesn't log a container commit event
+//
+// This is a temporary shim. Should be removed when builder stops using commit.
+func (daemon *Daemon) CommitBuildStep(c backend.CommitConfig) (image.ID, error) {
+	container, err := daemon.GetContainer(c.ContainerID)
+	if err != nil {
+		return "", err
+	}
+	c.ContainerMountLabel = container.MountLabel
+	c.ContainerOS = container.OS
+	c.ParentImageID = string(container.ImageID)
+	return daemon.commitImage(c)
+}