diff --git a/cmd/image-builder/upload.go b/cmd/image-builder/upload.go
index da03cf1..4e46ce2 100644
--- a/cmd/image-builder/upload.go
+++ b/cmd/image-builder/upload.go
@@ -89,6 +89,16 @@ func uploaderForCmdAWS(cmd *cobra.Command, bootMode *platform.BootMode) (cloud.U
 	if err != nil {
 		return nil, err
 	}
+	if bootMode == nil {
+		// If unset, default to BOOT_HYBIRD which translated
+		// to "uefi-prefered" when registering the image.
+		// This should give us wide compatibility. Ideally
+		// we would introspect the image but we have no
+		// metadata there right now.
+		// XXX: move this into the "images" library itself?
+		bootModeHybrid := platform.BOOT_HYBRID
+		bootMode = &bootModeHybrid
+	}
 
 	var missing []string
 	requiredArgs := []string{"aws-ami-name", "aws-bucket", "aws-region"}
@@ -126,8 +136,6 @@ func cmdUpload(cmd *cobra.Command, args []string) error {
 	}
 
 	imagePath := args[0]
-	// XXX: we need a way to introspect the image for bootmode here
-	// and/or error if no bootmode is specified
 	uploader, err := uploaderFor(cmd, uploadTo, nil)
 	if err != nil {
 		return err
diff --git a/cmd/image-builder/upload_test.go b/cmd/image-builder/upload_test.go
index 995de24..e75c8e2 100644
--- a/cmd/image-builder/upload_test.go
+++ b/cmd/image-builder/upload_test.go
@@ -92,7 +92,8 @@ func TestUploadWithAWSMock(t *testing.T) {
 		assert.Equal(t, regionName, "aws-region-1")
 		assert.Equal(t, bucketName, "aws-bucket-2")
 		assert.Equal(t, amiName, "aws-ami-3")
-		assert.Equal(t, &awscloud.UploaderOptions{TargetArch: tc.expectedUploadArch}, uploadOpts)
+		expectedBootMode := platform.BOOT_HYBRID
+		assert.Equal(t, &awscloud.UploaderOptions{TargetArch: tc.expectedUploadArch, BootMode: &expectedBootMode}, uploadOpts)
 
 		assert.Equal(t, 0, fa.checkCalls)
 		assert.Equal(t, 1, fa.uploadAndRegisterCalls)