diff --git a/exporter/containerimage/export.go b/exporter/containerimage/export.go
index ec5a6312..cdbe3469 100644
--- a/exporter/containerimage/export.go
+++ b/exporter/containerimage/export.go
@@ -8,6 +8,7 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
 	"github.com/moby/buildkit/exporter"
+	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/util/push"
 	"github.com/pkg/errors"
@@ -15,11 +16,10 @@ import (
 )
 
 const (
-	keyImageName        = "name"
-	keyPush             = "push"
-	keyInsecure         = "registry.insecure"
-	exporterImageConfig = "containerimage.config"
-	ociTypes            = "oci-mediatypes"
+	keyImageName = "name"
+	keyPush      = "push"
+	keyInsecure  = "registry.insecure"
+	ociTypes     = "oci-mediatypes"
 )
 
 type Opt struct {
@@ -67,7 +67,7 @@ func (e *imageExporter) Resolve(ctx context.Context, opt map[string]string) (exp
 				return nil, errors.Wrapf(err, "non-bool value specified for %s", k)
 			}
 			i.insecure = b
-		case exporterImageConfig:
+		case exptypes.ExporterImageConfigKey:
 			i.config = []byte(v)
 		case ociTypes:
 			if v == "" {
@@ -102,7 +102,7 @@ func (e *imageExporterInstance) Name() string {
 func (e *imageExporterInstance) Export(ctx context.Context, src exporter.Source) (map[string]string, error) {
 	ref := src.Ref
 	opt := src.Metadata
-	if config, ok := opt[exporterImageConfig]; ok {
+	if config, ok := opt[exptypes.ExporterImageConfigKey]; ok {
 		e.config = config
 	}
 	desc, err := e.opt.ImageWriter.Commit(ctx, ref, e.config, e.ociTypes)
diff --git a/exporter/oci/export.go b/exporter/oci/export.go
index 5be9d065..70256347 100644
--- a/exporter/oci/export.go
+++ b/exporter/oci/export.go
@@ -10,6 +10,7 @@ import (
 	"github.com/docker/distribution/reference"
 	"github.com/moby/buildkit/exporter"
 	"github.com/moby/buildkit/exporter/containerimage"
+	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/session/filesync"
 	"github.com/moby/buildkit/util/dockerexporter"
@@ -22,11 +23,10 @@ import (
 type ExporterVariant string
 
 const (
-	exporterImageConfig = "containerimage.config"
-	keyImageName        = "name"
-	VariantOCI          = "oci"
-	VariantDocker       = "docker"
-	ociTypes            = "oci-mediatypes"
+	keyImageName  = "name"
+	VariantOCI    = "oci"
+	VariantDocker = "docker"
+	ociTypes      = "oci-mediatypes"
 )
 
 type Opt struct {
@@ -62,7 +62,7 @@ func (e *imageExporter) Resolve(ctx context.Context, opt map[string]string) (exp
 	i := &imageExporterInstance{imageExporter: e, caller: caller}
 	for k, v := range opt {
 		switch k {
-		case exporterImageConfig:
+		case exptypes.ExporterImageConfigKey:
 			i.config = []byte(v)
 		case keyImageName:
 			parsed, err := reference.ParseNormalizedNamed(v)
@@ -108,7 +108,7 @@ func (e *imageExporterInstance) Name() string {
 func (e *imageExporterInstance) Export(ctx context.Context, src exporter.Source) (map[string]string, error) {
 	ref := src.Ref
 	opt := src.Metadata
-	if config, ok := opt[exporterImageConfig]; ok {
+	if config, ok := opt[exptypes.ExporterImageConfigKey]; ok {
 		e.config = config
 	}
 	desc, err := e.opt.ImageWriter.Commit(ctx, ref, e.config, e.ociTypes)
diff --git a/frontend/gateway/gateway.go b/frontend/gateway/gateway.go
index 068d92e3..e9b984f5 100644
--- a/frontend/gateway/gateway.go
+++ b/frontend/gateway/gateway.go
@@ -16,6 +16,7 @@ import (
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/executor"
+	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	"github.com/moby/buildkit/frontend"
 	pb "github.com/moby/buildkit/frontend/gateway/pb"
 	"github.com/moby/buildkit/identity"
@@ -37,9 +38,8 @@ import (
 )
 
 const (
-	keySource           = "source"
-	keyDevel            = "gateway-devel"
-	exporterImageConfig = "containerimage.config"
+	keySource = "source"
+	keyDevel  = "gateway-devel"
 )
 
 func NewGatewayFrontend(w frontend.WorkerInfos) frontend.Frontend {
@@ -97,7 +97,7 @@ func (gf *gatewayFrontend) Solve(ctx context.Context, llbBridge frontend.Fronten
 			return nil, errors.Errorf("invalid ref: %T", devRes.Ref.Sys())
 		}
 		rootFS = workerRef.ImmutableRef
-		config, ok := devRes.Metadata[exporterImageConfig]
+		config, ok := devRes.Metadata[exptypes.ExporterImageConfigKey]
 		if ok {
 			if err := json.Unmarshal(config, &img); err != nil {
 				return nil, err