diff --git a/config/fcos/v1_5_exp/schema.go b/config/fcos/v1_5_exp/schema.go
index 452450b5..5d0847fe 100644
--- a/config/fcos/v1_5_exp/schema.go
+++ b/config/fcos/v1_5_exp/schema.go
@@ -21,6 +21,7 @@ import (
 type Config struct {
 	base.Config `yaml:",inline"`
 	BootDevice  BootDevice `yaml:"boot_device"`
+	Extensions  Extensions `yaml:"extensions"`
 }
 
 type BootDevice struct {
@@ -38,3 +39,5 @@ type BootDeviceLuks struct {
 type BootDeviceMirror struct {
 	Devices []string `yaml:"devices"`
 }
+
+type Extensions []string
diff --git a/config/fcos/v1_5_exp/translate.go b/config/fcos/v1_5_exp/translate.go
index 21f1b786..c2c19f86 100644
--- a/config/fcos/v1_5_exp/translate.go
+++ b/config/fcos/v1_5_exp/translate.go
@@ -15,6 +15,8 @@
 package v1_5_exp
 
 import (
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 
 	baseutil "github.com/coreos/butane/base/util"
@@ -26,6 +28,7 @@ import (
 	"github.com/coreos/ignition/v2/config/v3_4_experimental/types"
 	"github.com/coreos/vcontext/path"
 	"github.com/coreos/vcontext/report"
+	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -78,6 +81,11 @@ func (c Config) ToIgn3_4Unvalidated(options common.TranslateOptions) (types.Conf
 			}
 		}
 	}
+
+	retp, tsp, rp := c.processPackages(options)
+	retConfig, ts := baseutil.MergeTranslatedConfigs(retp, tsp, ret, ts)
+	ret = retConfig.(types.Config)
+	r.Merge(rp)
 	return ret, ts, r
 }
 
@@ -292,3 +300,50 @@ func translateBootDeviceLuks(from BootDeviceLuks, options common.TranslateOption
 	tm.AddTranslation(path.New("yaml"), path.New("json"))
 	return
 }
+
+func (c Config) processPackages(options common.TranslateOptions) (types.Config, translate.TranslationSet, report.Report) {
+	yamlPath := path.New("yaml", "extensions")
+	ret := types.Config{}
+	ts := translate.NewTranslationSet("yaml", "json")
+	var r report.Report
+	if len(c.Extensions) == 0 {
+		return ret, ts, r
+	}
+
+	treeFileContents, err := yaml.Marshal(&struct {
+		Packages []string `yaml:"packages"`
+	}{
+		Packages: c.Extensions,
+	})
+	if err != nil {
+		r.AddOnError(yamlPath, err)
+		return ret, ts, r
+	}
+	fullYamlContents := append([]byte("# Generated by Butane\n\n"), treeFileContents...)
+	src, gzipped, err := baseutil.MakeDataURL(fullYamlContents, nil, !options.NoResourceAutoCompression)
+	if err != nil {
+		r.AddOnError(yamlPath, err)
+		return ret, ts, r
+	}
+	hash := sha256.New()
+	hash.Write([]byte(src))
+	sha := hex.EncodeToString(hash.Sum(nil))[0:7]
+	file := types.File{
+		Node: types.Node{
+			Path: "/etc/rpm-ostree/origin.d/extensions-" + sha + ".yaml",
+		},
+		FileEmbedded1: types.FileEmbedded1{
+			Contents: types.Resource{
+				Source: util.StrToPtr(src),
+			},
+			Mode: util.IntToPtr(0644),
+		},
+	}
+	if gzipped {
+		file.Contents.Compression = util.StrToPtr("gzip")
+	}
+
+	ret.Storage.Files = append(ret.Storage.Files, file)
+	ts.AddFromCommonSource(yamlPath, path.New("json", "storage"), ret.Storage)
+	return ret, ts, r
+}
diff --git a/config/fcos/v1_5_exp/translate_test.go b/config/fcos/v1_5_exp/translate_test.go
index 9f8e5610..282a7920 100644
--- a/config/fcos/v1_5_exp/translate_test.go
+++ b/config/fcos/v1_5_exp/translate_test.go
@@ -1417,3 +1417,59 @@ func TestTranslateBootDevice(t *testing.T) {
 		assert.NoError(t, translations.DebugVerifyCoverage(actual), "#%d: incomplete TranslationSet coverage", i)
 	}
 }
+
+// TestTranslateExtensions tests translating the Butane config extensions section.
+func TestTranslateExtensions(t *testing.T) {
+	tests := []struct {
+		in         Config
+		out        types.Config
+		exceptions []translate.Translation
+		report     report.Report
+	}{
+		// config with two extensions/packages
+		{
+			Config{
+				Extensions: []string{"strace", "zsh"},
+			},
+			types.Config{
+				Ignition: types.Ignition{
+					Version: "3.4.0-experimental",
+				},
+				Storage: types.Storage{
+					Files: []types.File{
+						{
+							Node: types.Node{
+								Path: "/etc/rpm-ostree/origin.d/extensions-e2ecf66.yaml",
+							},
+							FileEmbedded1: types.FileEmbedded1{
+								Contents: types.Resource{
+									Source: util.StrToPtr("data:;base64,IyBHZW5lcmF0ZWQgYnkgQnV0YW5lCgpwYWNrYWdlczoKICAgIC0gc3RyYWNlCiAgICAtIHpzaAo="),
+								},
+								Mode: util.IntToPtr(420),
+							},
+						},
+					},
+				},
+			},
+			[]translate.Translation{
+				{path.New("yaml", "version"), path.New("json", "ignition", "version")},
+				{path.New("yaml", "extensions"), path.New("json", "storage")},
+				{path.New("yaml", "extensions"), path.New("json", "storage", "files")},
+				{path.New("yaml", "extensions"), path.New("json", "storage", "files", 0)},
+				{path.New("yaml", "extensions"), path.New("json", "storage", "files", 0, "path")},
+				{path.New("yaml", "extensions"), path.New("json", "storage", "files", 0, "mode")},
+				{path.New("yaml", "extensions"), path.New("json", "storage", "files", 0, "contents")},
+				{path.New("yaml", "extensions"), path.New("json", "storage", "files", 0, "contents", "source")},
+			},
+			report.Report{},
+		},
+	}
+
+	for i, test := range tests {
+		actual, translations, r := test.in.ToIgn3_4Unvalidated(common.TranslateOptions{})
+		assert.Equal(t, test.out, actual, "#%d: translation mismatch", i)
+		assert.Equal(t, test.report, r, "#%d: report mismatch", i)
+		baseutil.VerifyTranslations(t, translations, test.exceptions, "#%d", i)
+		assert.NoError(t, translations.DebugVerifyCoverage(actual), "#%d: incomplete TranslationSet coverage", i)
+	}
+}
diff --git a/docs/config-fcos-v1_5-exp.md b/docs/config-fcos-v1_5-exp.md
index 8338bb4e..bc71f557 100644
--- a/docs/config-fcos-v1_5-exp.md
+++ b/docs/config-fcos-v1_5-exp.md
@@ -203,6 +203,7 @@ The Fedora CoreOS configuration is a YAML document conforming to the following s
     * **_threshold_** (int): sets the minimum number of pieces required to decrypt the device. Default is 1.
   * **_mirror_** (object): describes mirroring of the boot disk for fault tolerance.
     * **_devices_** (list of strings): the list of whole-disk devices (not partitions) to include in the disk array, referenced by their absolute path. At least two devices must be specified.
+* **extensions** (list of strings): a list of packages to layer on top of the OS.
 
 [part-types]: http://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs
 [rfc2397]: https://tools.ietf.org/html/rfc2397
diff --git a/docs/config-openshift-v4_10-exp.md b/docs/config-openshift-v4_10-exp.md
index 8ea3315e..3a6d58e8 100644
--- a/docs/config-openshift-v4_10-exp.md
+++ b/docs/config-openshift-v4_10-exp.md
@@ -156,6 +156,7 @@ The OpenShift configuration is a YAML document conforming to the following speci
     * **_threshold_** (int): sets the minimum number of pieces required to decrypt the device. Default is 1.
   * **_mirror_** (object): describes mirroring of the boot disk for fault tolerance.
     * **_devices_** (list of strings): the list of whole-disk devices (not partitions) to include in the disk array, referenced by their absolute path. At least two devices must be specified.
+* **extensions** (list of strings): a list of packages to layer on top of the OS.
 * **_openshift_** (object): describes miscellaneous OpenShift configuration. Respected when rendering to a MachineConfig, ignored when rendering directly to an Ignition config.
   * **_kernel_type_** (string): which kernel to use on the node. Must be `default` or `realtime`.
   * **_kernel_arguments_** (list of strings): arguments to be added to the kernel command line.