diff --git a/Makefile b/Makefile
index b08ca9a3b..a072ae57b 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@ lint:
 	@go test github.com/moby/tool/cmd/moby
 
 test: moby
-	./moby build test/test.yml
+	./moby build -output tar test/test.yml
 	rm moby test.tar
 
 PHONY: install
diff --git a/cmd/moby/build.go b/cmd/moby/build.go
index b44abbb1e..7e4570e5c 100644
--- a/cmd/moby/build.go
+++ b/cmd/moby/build.go
@@ -10,6 +10,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	log "github.com/Sirupsen/logrus"
@@ -17,8 +18,30 @@ import (
 
 const defaultNameForStdin = "moby"
 
+type outputList []string
+
+func (o *outputList) String() string {
+	return fmt.Sprint(*o)
+}
+
+func (o *outputList) Set(value string) error {
+	// allow comma seperated options or multiple options
+	for _, cs := range strings.Split(value, ",") {
+		*o = append(*o, cs)
+	}
+	return nil
+}
+
 // Process the build arguments and execute build
 func build(args []string) {
+	var buildOut outputList
+
+	outputTypes := []string{}
+	for k := range outFuns {
+		outputTypes = append(outputTypes, k)
+	}
+	sort.Strings(outputTypes)
+
 	buildCmd := flag.NewFlagSet("build", flag.ExitOnError)
 	buildCmd.Usage = func() {
 		fmt.Printf("USAGE: %s build [options] <file>[.yml] | -\n\n", os.Args[0])
@@ -27,12 +50,19 @@ func build(args []string) {
 	}
 	buildName := buildCmd.String("name", "", "Name to use for output files")
 	buildPull := buildCmd.Bool("pull", false, "Always pull images")
+	buildCmd.Var(&buildOut, "output", "Output types to create [ "+strings.Join(outputTypes, " ")+" ]")
 
 	if err := buildCmd.Parse(args); err != nil {
 		log.Fatal("Unable to parse args")
 	}
 	remArgs := buildCmd.Args()
 
+	if len(buildOut) == 0 {
+		buildOut = outputList{"kernel+initrd"}
+	}
+
+	log.Debugf("Outputs selected: %s", buildOut.String())
+
 	if len(remArgs) == 0 {
 		fmt.Println("Please specify a configuration file")
 		buildCmd.Usage()
@@ -71,7 +101,7 @@ func build(args []string) {
 	image := buildInternal(m, name, *buildPull)
 
 	log.Infof("Create outputs:")
-	err = outputs(m, name, image)
+	err = outputs(name, image, buildOut)
 	if err != nil {
 		log.Fatalf("Error writing outputs: %v", err)
 	}
diff --git a/cmd/moby/config.go b/cmd/moby/config.go
index d52e54bc2..dd445e0bf 100644
--- a/cmd/moby/config.go
+++ b/cmd/moby/config.go
@@ -38,9 +38,6 @@ type Moby struct {
 		Contents  string
 		Source    string
 	}
-	Outputs []struct {
-		Format string
-	}
 }
 
 // TrustConfig is the type of a content trust config
diff --git a/cmd/moby/config_test.go b/cmd/moby/config_test.go
index e5554057a..bc47860e5 100644
--- a/cmd/moby/config_test.go
+++ b/cmd/moby/config_test.go
@@ -12,7 +12,7 @@ import (
 func TestOverrides(t *testing.T) {
 	var yamlCaps = []string{"CAP_SYS_ADMIN"}
 
-	var yaml MobyImage = MobyImage{
+	var yaml = MobyImage{
 		Name:         "test",
 		Image:        "testimage",
 		Capabilities: &yamlCaps,
@@ -20,7 +20,7 @@ func TestOverrides(t *testing.T) {
 
 	var labelCaps = []string{"CAP_SYS_CHROOT"}
 
-	var label MobyImage = MobyImage{
+	var label = MobyImage{
 		Capabilities: &labelCaps,
 		Cwd:          "/label/directory",
 	}
diff --git a/cmd/moby/output.go b/cmd/moby/output.go
index 21989dc99..60fb65fa9 100644
--- a/cmd/moby/output.go
+++ b/cmd/moby/output.go
@@ -21,94 +21,118 @@ const (
 	vmdk = "linuxkit/mkimage-vmdk:182b541474ca7965c8e8f987389b651859f760da@sha256:99638c5ddb17614f54c6b8e11bd9d49d1dea9d837f38e0f6c1a5f451085d449b"
 )
 
-func outputs(m Moby, base string, image []byte) error {
-	log.Debugf("output: %s %s", m.Outputs, base)
+var outFuns = map[string]func(string, []byte) error{
+	"tar": func(base string, image []byte) error {
+		err := outputTar(base, image)
+		if err != nil {
+			return fmt.Errorf("Error writing tar output: %v", err)
+		}
+		return nil
+	},
+	"kernel+initrd": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputKernelInitrd(base, kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writing kernel+initrd output: %v", err)
+		}
+		return nil
+	},
+	"iso-bios": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImg(bios, base+".iso", kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writing iso-bios output: %v", err)
+		}
+		return nil
+	},
+	"iso-efi": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImg(efi, base+"-efi.iso", kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writing iso-efi output: %v", err)
+		}
+		return nil
+	},
+	"img-gz": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImgSize(img, base+".img.gz", kernel, initrd, cmdline, "1G")
+		if err != nil {
+			return fmt.Errorf("Error writing img-gz output: %v", err)
+		}
+		return nil
+	},
+	"gcp-img": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImg(gcp, base+".img.tar.gz", kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writing gcp-img output: %v", err)
+		}
+		return nil
+	},
+	"qcow2": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImg(qcow, base+".qcow2", kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writing qcow2 output: %v", err)
+		}
+		return nil
+	},
+	"vhd": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImg(vhd, base+".vhd", kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writingvhd output: %v", err)
+		}
+		return nil
+	},
+	"vmdk": func(base string, image []byte) error {
+		kernel, initrd, cmdline, err := tarToInitrd(image)
+		if err != nil {
+			return fmt.Errorf("Error converting to initrd: %v", err)
+		}
+		err = outputImg(vmdk, base+".vmdk", kernel, initrd, cmdline)
+		if err != nil {
+			return fmt.Errorf("Error writing vmdk output: %v", err)
+		}
+		return nil
+	},
+}
 
-	for _, o := range m.Outputs {
-		switch o.Format {
-		case "tar":
-			err := outputTar(base, image)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "kernel+initrd":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputKernelInitrd(base, kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "iso-bios":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImg(bios, base+".iso", kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "iso-efi":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImg(efi, base+"-efi.iso", kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "img-gz":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImgSize(img, base+".img.gz", kernel, initrd, cmdline, "1G")
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "gcp-img":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImg(gcp, base+".img.tar.gz", kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "qcow", "qcow2":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImg(qcow, base+".qcow2", kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "vhd":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImg(vhd, base+".vhd", kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "vmdk":
-			kernel, initrd, cmdline, err := tarToInitrd(image)
-			if err != nil {
-				return fmt.Errorf("Error converting to initrd: %v", err)
-			}
-			err = outputImg(vmdk, base+".vmdk", kernel, initrd, cmdline)
-			if err != nil {
-				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
-			}
-		case "":
-			return fmt.Errorf("No format specified for output")
-		default:
-			return fmt.Errorf("Unknown output type %s", o.Format)
+func outputs(base string, image []byte, out outputList) error {
+	log.Debugf("output: %v %s", out, base)
+
+	for _, o := range out {
+		f := outFuns[o]
+		if f == nil {
+			return fmt.Errorf("Unknown output type %s", o)
+		}
+		err := f(base, image)
+		if err != nil {
+			return err
 		}
 	}
+
 	return nil
 }
 
diff --git a/cmd/moby/schema.go b/cmd/moby/schema.go
index 3b26164c0..75a70b73b 100644
--- a/cmd/moby/schema.go
+++ b/cmd/moby/schema.go
@@ -29,17 +29,6 @@ var schema = string(`
         "type": "array",
         "items": { "$ref": "#/definitions/file" }
     },
-    "output": {
-      "type": "object",
-      "additionalProperties": false,
-      "properties": {
-        "format": {"type": "string"}
-      }
-    },
-    "outputs": {
-        "type": "array",
-        "items": { "$ref": "#/definitions/output" }
-    },
     "trust": {
       "type": "object",
       "additionalProperties": false,
@@ -116,8 +105,7 @@ var schema = string(`
     "onboot": { "$ref": "#/definitions/images" },
     "services": { "$ref": "#/definitions/images" },
     "trust": { "$ref": "#/definitions/trust" },
-    "files": { "$ref": "#/definitions/files" },
-    "outputs": { "$ref": "#/definitions/outputs" }
+    "files": { "$ref": "#/definitions/files" }
   }
 }
 `)
diff --git a/test/test.yml b/test/test.yml
index c316cadc0..f0e21126e 100644
--- a/test/test.yml
+++ b/test/test.yml
@@ -56,5 +56,3 @@ trust:
     - linuxkit/kernel
     - linuxkit/binfmt
     - linuxkit/rngd
-outputs:
-  - format: tar