diff --git a/api/types/backend/disk_usage.go b/api/types/backend/disk_usage.go
new file mode 100644
index 0000000000..9e0c070035
--- /dev/null
+++ b/api/types/backend/disk_usage.go
@@ -0,0 +1,29 @@
+package backend
+
+import (
+	"github.com/moby/moby/api/types/build"
+	"github.com/moby/moby/api/types/container"
+	"github.com/moby/moby/api/types/image"
+	"github.com/moby/moby/api/types/volume"
+)
+
+// DiskUsageOptions holds parameters for system disk usage query.
+type DiskUsageOptions struct {
+	// Containers controls whether container disk usage should be computed.
+	Containers bool
+
+	// Images controls whether image disk usage should be computed.
+	Images bool
+
+	// Volumes controls whether volume disk usage should be computed.
+	Volumes bool
+}
+
+// DiskUsage contains the information returned by the backend for the
+// GET "/system/df" endpoint.
+type DiskUsage struct {
+	Images     *image.DiskUsage
+	Containers *container.DiskUsage
+	Volumes    *volume.DiskUsage
+	BuildCache *build.CacheDiskUsage
+}
diff --git a/api/types/system/disk_usage.go b/api/types/system/disk_usage.go
deleted file mode 100644
index 333a7c7fc4..0000000000
--- a/api/types/system/disk_usage.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package system
-
-import (
-	"github.com/moby/moby/api/types/build"
-	"github.com/moby/moby/api/types/container"
-	"github.com/moby/moby/api/types/image"
-	"github.com/moby/moby/api/types/volume"
-)
-
-// DiskUsage contains response of Engine API for API 1.49 and greater:
-// GET "/system/df"
-type DiskUsage struct {
-	Images     *image.DiskUsage
-	Containers *container.DiskUsage
-	Volumes    *volume.DiskUsage
-	BuildCache *build.CacheDiskUsage
-}
diff --git a/daemon/disk_usage.go b/daemon/disk_usage.go
index b6e4a0daa3..b6ee2a9ba9 100644
--- a/daemon/disk_usage.go
+++ b/daemon/disk_usage.go
@@ -4,11 +4,10 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/docker/docker/daemon/server/router/system"
+	"github.com/moby/moby/api/types/backend"
 	"github.com/moby/moby/api/types/container"
 	"github.com/moby/moby/api/types/filters"
 	"github.com/moby/moby/api/types/image"
-	systemtypes "github.com/moby/moby/api/types/system"
 	"github.com/moby/moby/api/types/volume"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
@@ -103,10 +102,10 @@ func (daemon *Daemon) layerDiskUsage(ctx context.Context) (int64, error) {
 
 // SystemDiskUsage returns information about the daemon data disk usage.
 // Callers must not mutate contents of the returned fields.
-func (daemon *Daemon) SystemDiskUsage(ctx context.Context, opts system.DiskUsageOptions) (*systemtypes.DiskUsage, error) {
+func (daemon *Daemon) SystemDiskUsage(ctx context.Context, opts backend.DiskUsageOptions) (*backend.DiskUsage, error) {
 	eg, ctx := errgroup.WithContext(ctx)
 
-	du := &systemtypes.DiskUsage{}
+	du := &backend.DiskUsage{}
 	if opts.Containers {
 		eg.Go(func() (err error) {
 			du.Containers, err = daemon.containerDiskUsage(ctx)
diff --git a/daemon/server/router/system/backend.go b/daemon/server/router/system/backend.go
index 6da7825b54..84d8e28497 100644
--- a/daemon/server/router/system/backend.go
+++ b/daemon/server/router/system/backend.go
@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/moby/moby/api/types"
+	"github.com/moby/moby/api/types/backend"
 	"github.com/moby/moby/api/types/build"
 	"github.com/moby/moby/api/types/events"
 	"github.com/moby/moby/api/types/filters"
@@ -13,24 +14,12 @@ import (
 	"github.com/moby/moby/api/types/system"
 )
 
-// DiskUsageOptions holds parameters for system disk usage query.
-type DiskUsageOptions struct {
-	// Containers controls whether container disk usage should be computed.
-	Containers bool
-
-	// Images controls whether image disk usage should be computed.
-	Images bool
-
-	// Volumes controls whether volume disk usage should be computed.
-	Volumes bool
-}
-
 // Backend is the methods that need to be implemented to provide
 // system specific functionality.
 type Backend interface {
 	SystemInfo(context.Context) (*system.Info, error)
 	SystemVersion(context.Context) (types.Version, error)
-	SystemDiskUsage(ctx context.Context, opts DiskUsageOptions) (*system.DiskUsage, error)
+	SystemDiskUsage(ctx context.Context, opts backend.DiskUsageOptions) (*backend.DiskUsage, error)
 	SubscribeToEvents(since, until time.Time, ef filters.Args) ([]events.Message, chan interface{})
 	UnsubscribeFromEvents(chan interface{})
 	AuthenticateToRegistry(ctx context.Context, authConfig *registry.AuthConfig) (string, error)
diff --git a/daemon/server/router/system/system_routes.go b/daemon/server/router/system/system_routes.go
index afb1bbbdc8..ec5f817c6a 100644
--- a/daemon/server/router/system/system_routes.go
+++ b/daemon/server/router/system/system_routes.go
@@ -15,6 +15,7 @@ import (
 	"github.com/docker/docker/daemon/server/router/build"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/moby/moby/api/types"
+	"github.com/moby/moby/api/types/backend"
 	buildtypes "github.com/moby/moby/api/types/build"
 	"github.com/moby/moby/api/types/events"
 	"github.com/moby/moby/api/types/filters"
@@ -183,11 +184,11 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 
 	eg, ctx := errgroup.WithContext(ctx)
 
-	var systemDiskUsage *system.DiskUsage
+	var systemDiskUsage *backend.DiskUsage
 	if getContainers || getImages || getVolumes {
 		eg.Go(func() error {
 			var err error
-			systemDiskUsage, err = s.backend.SystemDiskUsage(ctx, DiskUsageOptions{
+			systemDiskUsage, err = s.backend.SystemDiskUsage(ctx, backend.DiskUsageOptions{
 				Containers: getContainers,
 				Images:     getImages,
 				Volumes:    getVolumes,
@@ -238,7 +239,7 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		}
 	}
 
-	du := system.DiskUsage{}
+	du := backend.DiskUsage{}
 	if getBuildCache {
 		du.BuildCache = &buildtypes.CacheDiskUsage{
 			TotalSize: builderSize,
diff --git a/vendor/github.com/moby/moby/api/types/backend/disk_usage.go b/vendor/github.com/moby/moby/api/types/backend/disk_usage.go
new file mode 100644
index 0000000000..9e0c070035
--- /dev/null
+++ b/vendor/github.com/moby/moby/api/types/backend/disk_usage.go
@@ -0,0 +1,29 @@
+package backend
+
+import (
+	"github.com/moby/moby/api/types/build"
+	"github.com/moby/moby/api/types/container"
+	"github.com/moby/moby/api/types/image"
+	"github.com/moby/moby/api/types/volume"
+)
+
+// DiskUsageOptions holds parameters for system disk usage query.
+type DiskUsageOptions struct {
+	// Containers controls whether container disk usage should be computed.
+	Containers bool
+
+	// Images controls whether image disk usage should be computed.
+	Images bool
+
+	// Volumes controls whether volume disk usage should be computed.
+	Volumes bool
+}
+
+// DiskUsage contains the information returned by the backend for the
+// GET "/system/df" endpoint.
+type DiskUsage struct {
+	Images     *image.DiskUsage
+	Containers *container.DiskUsage
+	Volumes    *volume.DiskUsage
+	BuildCache *build.CacheDiskUsage
+}
diff --git a/vendor/github.com/moby/moby/api/types/system/disk_usage.go b/vendor/github.com/moby/moby/api/types/system/disk_usage.go
deleted file mode 100644
index 333a7c7fc4..0000000000
--- a/vendor/github.com/moby/moby/api/types/system/disk_usage.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package system
-
-import (
-	"github.com/moby/moby/api/types/build"
-	"github.com/moby/moby/api/types/container"
-	"github.com/moby/moby/api/types/image"
-	"github.com/moby/moby/api/types/volume"
-)
-
-// DiskUsage contains response of Engine API for API 1.49 and greater:
-// GET "/system/df"
-type DiskUsage struct {
-	Images     *image.DiskUsage
-	Containers *container.DiskUsage
-	Volumes    *volume.DiskUsage
-	BuildCache *build.CacheDiskUsage
-}