diff --git a/USAGE.md b/USAGE.md
index c0c5530a..a41583c2 100644
--- a/USAGE.md
+++ b/USAGE.md
@@ -10,6 +10,10 @@ You may want to override `$ENVOY_VERSIONS_URL` to supply custom builds or
 otherwise control the source of Envoy binaries. When overriding, validate
 your JSON first: https://archive.tetratelabs.io/release-versions-schema.json
 
+Advanced:
+`FUNC_E_PLATFORM` overrides the host OS and architecture of Envoy binaries.
+This value must be constant within a `$FUNC_E_HOME`.
+
 # Commands
 
 | Name | Usage |
@@ -26,3 +30,4 @@ your JSON first: https://archive.tetratelabs.io/release-versions-schema.json
 | ---- | ----- | ------- |
 | FUNC_E_HOME | func-e home directory (location of installed versions and run archives) | ${HOME}/.func-e |
 | ENVOY_VERSIONS_URL | URL of Envoy versions JSON | https://archive.tetratelabs.io/envoy/envoy-versions.json |
+| FUNC_E_PLATFORM | the host OS and architecture of Envoy binaries. Ex. darwin/arm64 | $GOOS/$GOARCH |
diff --git a/internal/cmd/app.go b/internal/cmd/app.go
index 3361f212..eef390a2 100644
--- a/internal/cmd/app.go
+++ b/internal/cmd/app.go
@@ -29,7 +29,7 @@ import (
 // NewApp create a new root command. The globals.GlobalOpts parameter allows tests to scope overrides, which avoids
 // having to define a flag for everything needed in tests.
 func NewApp(o *globals.GlobalOpts) *cli.App {
-	var envoyVersionsURL, homeDir string
+	var envoyVersionsURL, homeDir, platform string
 	lastKnownEnvoy := getLastKnownEnvoy(o)
 
 	app := cli.NewApp()
@@ -47,7 +47,11 @@ func NewApp(o *globals.GlobalOpts) *cli.App {
 
    You may want to override ` + "`$ENVOY_VERSIONS_URL`" + ` to supply custom builds or
    otherwise control the source of Envoy binaries. When overriding, validate
-   your JSON first: https://archive.tetratelabs.io/release-versions-schema.json`
+   your JSON first: https://archive.tetratelabs.io/release-versions-schema.json
+
+   Advanced:
+   ` + "`FUNC_E_PLATFORM`" + ` overrides the host OS and architecture of Envoy binaries.
+   This value must be constant within a ` + "`$FUNC_E_HOME`" + `.`
 	app.Version = string(o.Version)
 	app.Flags = []cli.Flag{
 		&cli.StringFlag{
@@ -63,8 +67,17 @@ func NewApp(o *globals.GlobalOpts) *cli.App {
 			DefaultText: globals.DefaultEnvoyVersionsURL,
 			Destination: &envoyVersionsURL,
 			EnvVars:     []string{"ENVOY_VERSIONS_URL"},
-		}}
+		},
+		&cli.StringFlag{
+			Name:        "platform",
+			Usage:       "the host OS and architecture of Envoy binaries. Ex. darwin/arm64",
+			DefaultText: "$GOOS/$GOARCH",
+			Destination: &platform,
+			EnvVars:     []string{"FUNC_E_PLATFORM"},
+		},
+	}
 	app.Before = func(c *cli.Context) error {
+		setPlatform(o, platform)
 		if err := setHomeDir(o, homeDir); err != nil {
 			return err
 		}
@@ -103,6 +116,17 @@ var helpCommand = &cli.Command{
 	},
 }
 
+func setPlatform(o *globals.GlobalOpts, platform string) {
+	if o.Platform != "" { // overridden for tests
+		return
+	}
+	if platform != "" { // set by user
+		o.Platform = version.Platform(platform)
+	} else {
+		o.Platform = globals.DefaultPlatform
+	}
+}
+
 func setEnvoyVersionsURL(o *globals.GlobalOpts, versionsURL string) error {
 	if o.EnvoyVersionsURL != "" { // overridden for tests
 		return nil
diff --git a/internal/cmd/app_test.go b/internal/cmd/app_test.go
index 5ed596e1..d1176ee4 100644
--- a/internal/cmd/app_test.go
+++ b/internal/cmd/app_test.go
@@ -114,6 +114,49 @@ func TestHomeDir(t *testing.T) {
 	}
 }
 
+func TestPlatformArg(t *testing.T) {
+	type testCase struct {
+		name string
+		args []string
+		// setup returns a tear-down function
+		setup    func() func()
+		expected version.Platform
+	}
+
+	tests := []testCase{
+		{
+			name: "FUNC_E_PLATFORM env",
+			args: []string{"func-e"},
+			setup: func() func() {
+				return morerequire.RequireSetenv(t, "FUNC_E_PLATFORM", "linux/amd64")
+			},
+			expected: version.Platform("linux/amd64"),
+		},
+		{
+			name:     "--platform flag",
+			args:     []string{"func-e", "--platform", "darwin/amd64"},
+			expected: version.Platform("darwin/amd64"),
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc // pin! see https://github.com/kyoh86/scopelint for why
+
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.setup != nil {
+				tearDown := tc.setup()
+				defer tearDown()
+			}
+
+			o := &globals.GlobalOpts{}
+			err := runTestCommand(t, o, tc.args)
+			require.NoError(t, err)
+			require.Equal(t, tc.expected, o.Platform)
+		})
+	}
+
+}
+
 func TestEnvoyVersionsURL(t *testing.T) {
 	type testCase struct {
 		name string
diff --git a/internal/cmd/run.go b/internal/cmd/run.go
index a696e9bb..2692c717 100644
--- a/internal/cmd/run.go
+++ b/internal/cmd/run.go
@@ -71,7 +71,7 @@ state. On exit, these archive into ` + "`$FUNC_E_HOME/runs/$epochtime.tar.gz`",
 			return nil
 		},
 		Action: func(c *cli.Context) error {
-			if err := initializeRunOpts(c.Context, o, globals.CurrentPlatform, envoyVersion); err != nil {
+			if err := initializeRunOpts(c.Context, o, envoyVersion); err != nil {
 				return err
 			}
 			r := envoy.NewRuntime(&o.RunOpts)
@@ -111,10 +111,10 @@ state. On exit, these archive into ` + "`$FUNC_E_HOME/runs/$epochtime.tar.gz`",
 // initializeRunOpts allows us to default values when not overridden for tests.
 // The version parameter correlates with the globals.GlobalOpts EnvoyPath which is installed if needed.
 // Notably, this creates and sets a globals.GlobalOpts WorkingDirectory for Envoy, and any files that precede it.
-func initializeRunOpts(ctx context.Context, o *globals.GlobalOpts, p version.Platform, v version.Version) error {
+func initializeRunOpts(ctx context.Context, o *globals.GlobalOpts, v version.Version) error {
 	runOpts := &o.RunOpts
 	if o.EnvoyPath == "" { // not overridden for tests
-		envoyPath, err := envoy.InstallIfNeeded(ctx, o, p, v)
+		envoyPath, err := envoy.InstallIfNeeded(ctx, o, v)
 		if err != nil {
 			return err
 		}
@@ -144,7 +144,7 @@ func setHomeEnvoyVersion(ctx context.Context, o *globals.GlobalOpts) error {
 
 	// First time install: look up the latest version, which may be newer than version.LastKnownEnvoy!
 	fmt.Fprintln(o.Out, "looking up latest version") //nolint
-	m, err := envoy.FuncEVersions(ctx, o.EnvoyVersionsURL, globals.CurrentPlatform, o.Version)
+	m, err := envoy.FuncEVersions(ctx, o.EnvoyVersionsURL, o.Platform, o.Version)
 	if err != nil {
 		return NewValidationError(`couldn't read latest version from %s: %s`, o.EnvoyVersionsURL, err)
 	}
diff --git a/internal/cmd/testdata/func-e_help.txt b/internal/cmd/testdata/func-e_help.txt
index 5407ce0e..99d2cae9 100644
--- a/internal/cmd/testdata/func-e_help.txt
+++ b/internal/cmd/testdata/func-e_help.txt
@@ -13,6 +13,10 @@ USAGE:
    otherwise control the source of Envoy binaries. When overriding, validate
    your JSON first: https://archive.tetratelabs.io/release-versions-schema.json
 
+   Advanced:
+   `FUNC_E_PLATFORM` overrides the host OS and architecture of Envoy binaries.
+   This value must be constant within a `$FUNC_E_HOME`.
+
 VERSION:
    1.0
 
@@ -25,4 +29,5 @@ COMMANDS:
 GLOBAL OPTIONS:
    --home-dir value            func-e home directory (location of installed versions and run archives) (default: ${HOME}/.func-e) [$FUNC_E_HOME]
    --envoy-versions-url value  URL of Envoy versions JSON (default: https://archive.tetratelabs.io/envoy/envoy-versions.json) [$ENVOY_VERSIONS_URL]
+   --platform value            the host OS and architecture of Envoy binaries. Ex. darwin/arm64 (default: $GOOS/$GOARCH) [$FUNC_E_PLATFORM]
    --version, -v               print the version (default: false)
diff --git a/internal/cmd/use.go b/internal/cmd/use.go
index 707569a8..3134d4c0 100644
--- a/internal/cmd/use.go
+++ b/internal/cmd/use.go
@@ -44,7 +44,7 @@ $ func-e use %s`, envoy.CurrentVersionWorkingDirFile, envoy.CurrentVersionHomeDi
 		Before: validateVersionArg,
 		Action: func(c *cli.Context) error {
 			v := version.Version(c.Args().First())
-			if _, err := envoy.InstallIfNeeded(c.Context, o, globals.CurrentPlatform, v); err != nil {
+			if _, err := envoy.InstallIfNeeded(c.Context, o, v); err != nil {
 				return err
 			}
 			return envoy.WriteCurrentVersion(v, o.HomeDir)
diff --git a/internal/cmd/versions.go b/internal/cmd/versions.go
index ab06e603..d767f0ae 100644
--- a/internal/cmd/versions.go
+++ b/internal/cmd/versions.go
@@ -50,9 +50,9 @@ func NewVersionsCmd(o *globals.GlobalOpts) *cli.Command {
 			currentVersion, currentVersionSource, _ := envoy.CurrentVersion(o.HomeDir)
 
 			if c.Bool("all") {
-				if ev, err := envoy.FuncEVersions(c.Context, o.EnvoyVersionsURL, globals.CurrentPlatform, o.Version); err != nil {
+				if ev, err := envoy.FuncEVersions(c.Context, o.EnvoyVersionsURL, o.Platform, o.Version); err != nil {
 					return err
-				} else if err := addAvailableVersions(&rows, ev.Versions, globals.CurrentPlatform); err != nil {
+				} else if err := addAvailableVersions(&rows, ev.Versions, o.Platform); err != nil {
 					return err
 				}
 			}
diff --git a/internal/envoy/http_test.go b/internal/envoy/http_test.go
index da51ee25..4924fb7e 100644
--- a/internal/envoy/http_test.go
+++ b/internal/envoy/http_test.go
@@ -33,7 +33,7 @@ func TestHttpGet_AddsDefaultHeaders(t *testing.T) {
 	}))
 	defer ts.Close()
 
-	res, err := httpGet(context.Background(), ts.URL, globals.CurrentPlatform, "dev")
+	res, err := httpGet(context.Background(), ts.URL, globals.DefaultPlatform, "dev")
 	require.NoError(t, err)
 
 	defer res.Body.Close()
diff --git a/internal/envoy/install.go b/internal/envoy/install.go
index f1852678..d8d964c2 100644
--- a/internal/envoy/install.go
+++ b/internal/envoy/install.go
@@ -35,39 +35,39 @@ import (
 var binEnvoy = filepath.Join("bin", "envoy"+moreos.Exe)
 
 // InstallIfNeeded downloads an Envoy binary corresponding to the given version and returns a path to it or an error.
-func InstallIfNeeded(ctx context.Context, o *globals.GlobalOpts, p version.Platform, v version.Version) (string, error) {
+func InstallIfNeeded(ctx context.Context, o *globals.GlobalOpts, v version.Version) (string, error) {
 	installPath := filepath.Join(o.HomeDir, "versions", string(v))
 	envoyPath := filepath.Join(installPath, binEnvoy)
 	_, err := os.Stat(envoyPath)
 	switch {
 	case os.IsNotExist(err):
 		var ev version.ReleaseVersions // Get version metadata for what we will install
-		ev, err = FuncEVersions(ctx, o.EnvoyVersionsURL, p, v)
+		ev, err = FuncEVersions(ctx, o.EnvoyVersionsURL, o.Platform, v)
 		if err != nil {
 			return "", err
 		}
 
-		tarballURL := ev.Versions[v].Tarballs[p] // Ensure there is a version for this platform
+		tarballURL := ev.Versions[v].Tarballs[o.Platform] // Ensure there is a version for this platform
 		if tarballURL == "" {
-			return "", fmt.Errorf("couldn't find version %q for platform %q", v, p)
+			return "", fmt.Errorf("couldn't find version %q for platform %q", v, o.Platform)
 		}
 
 		tarball := version.Tarball(path.Base(string(tarballURL)))
 		sha256Sum := ev.SHA256Sums[tarball]
 		if len(sha256Sum) != 64 {
-			return "", fmt.Errorf("couldn't find sha256Sum of version %q for platform %q: %w", v, p, err)
+			return "", fmt.Errorf("couldn't find sha256Sum of version %q for platform %q: %w", v, o.Platform, err)
 		}
 
 		var mtime time.Time // Create a directory for the version, preserving the release date as its mtime
 		if mtime, err = time.Parse("2006-01-02", string(ev.Versions[v].ReleaseDate)); err != nil {
-			return "", fmt.Errorf("couldn't find releaseDate of version %q for platform %q: %w", v, p, err)
+			return "", fmt.Errorf("couldn't find releaseDate of version %q for platform %q: %w", v, o.Platform, err)
 		}
 		if err = os.MkdirAll(installPath, 0750); err != nil {
 			return "", fmt.Errorf("unable to create directory %q: %w", installPath, err)
 		}
 
-		fmt.Fprintln(o.Out, "downloading", tarballURL)                                   //nolint
-		if err = untarEnvoy(ctx, installPath, tarballURL, sha256Sum, p, v); err != nil { //nolint
+		fmt.Fprintln(o.Out, "downloading", tarballURL)                                            //nolint
+		if err = untarEnvoy(ctx, installPath, tarballURL, sha256Sum, o.Platform, v); err != nil { //nolint
 			return "", err
 		}
 		if err = os.Chtimes(installPath, mtime, mtime); err != nil { // overwrite the mtime to preserve it in the list
diff --git a/internal/envoy/install_test.go b/internal/envoy/install_test.go
index bdf5cee4..63424997 100644
--- a/internal/envoy/install_test.go
+++ b/internal/envoy/install_test.go
@@ -54,7 +54,7 @@ func TestUntarEnvoyError(t *testing.T) {
 
 	url := version.TarballURL(server.URL + "/file.tar.gz")
 	t.Run("error on incorrect URL", func(t *testing.T) {
-		err := untarEnvoy(ctx, dst, url, tarballSHA256sum, globals.CurrentPlatform, "dev")
+		err := untarEnvoy(ctx, dst, url, tarballSHA256sum, globals.DefaultPlatform, "dev")
 		require.EqualError(t, err, fmt.Sprintf(`received 404 status code from %s`, url))
 	})
 
@@ -62,7 +62,7 @@ func TestUntarEnvoyError(t *testing.T) {
 		w.WriteHeader(200)
 	}
 	t.Run("error on empty", func(t *testing.T) {
-		err := untarEnvoy(ctx, dst, url, tarballSHA256sum, globals.CurrentPlatform, "dev")
+		err := untarEnvoy(ctx, dst, url, tarballSHA256sum, globals.DefaultPlatform, "dev")
 		require.EqualError(t, err, fmt.Sprintf(`error untarring %s: EOF`, url))
 	})
 
@@ -71,7 +71,7 @@ func TestUntarEnvoyError(t *testing.T) {
 		w.Write([]byte("mary had a little lamb")) //nolint
 	}
 	t.Run("error on not a tar", func(t *testing.T) {
-		err := untarEnvoy(ctx, dst, url, tarballSHA256sum, globals.CurrentPlatform, "dev")
+		err := untarEnvoy(ctx, dst, url, tarballSHA256sum, globals.DefaultPlatform, "dev")
 		require.EqualError(t, err, fmt.Sprintf(`error untarring %s: gzip: invalid header`, url))
 	})
 
@@ -80,7 +80,7 @@ func TestUntarEnvoyError(t *testing.T) {
 		w.Write(tarball) //nolint
 	}
 	t.Run("error on wrong sha256sum a tar", func(t *testing.T) {
-		err := untarEnvoy(ctx, dst, url, "cafebabe", globals.CurrentPlatform, "dev")
+		err := untarEnvoy(ctx, dst, url, "cafebabe", globals.DefaultPlatform, "dev")
 		require.EqualError(t, err, fmt.Sprintf(`expected SHA-256 sum "cafebabe", but have "%s" from %s`, tarballSHA256sum, url))
 	})
 }
@@ -99,7 +99,7 @@ func TestUntarEnvoy(t *testing.T) {
 	}))
 	defer server.Close()
 
-	err := untarEnvoy(context.Background(), tempDir, version.TarballURL(server.URL), tarballSHA256sum, globals.CurrentPlatform, "dev")
+	err := untarEnvoy(context.Background(), tempDir, version.TarballURL(server.URL), tarballSHA256sum, globals.DefaultPlatform, "dev")
 	require.NoError(t, err)
 	require.FileExists(t, filepath.Join(tempDir, binEnvoy))
 }
@@ -110,7 +110,7 @@ func TestInstallIfNeeded_ErrorOnIncorrectURL(t *testing.T) {
 
 	o.EnvoyVersionsURL += "/varsionz.json"
 
-	_, err := InstallIfNeeded(o.ctx, &o.GlobalOpts, globals.CurrentPlatform, version.LastKnownEnvoy)
+	_, err := InstallIfNeeded(o.ctx, &o.GlobalOpts, version.LastKnownEnvoy)
 	require.EqualError(t, err, "received 404 status code from "+o.EnvoyVersionsURL)
 	require.Empty(t, o.Out.(*bytes.Buffer))
 }
@@ -141,9 +141,10 @@ func TestInstallIfNeeded_Validates(t *testing.T) {
 
 	for _, tt := range tests {
 		tc := tt
+		o.Platform = tt.p
 		t.Run(tc.name, func(t *testing.T) {
 			o.Out = new(bytes.Buffer)
-			_, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, tc.p, tc.v)
+			_, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, tc.v)
 			require.EqualError(t, e, tc.expectedErr)
 			require.Empty(t, o.Out.(*bytes.Buffer))
 		})
@@ -155,7 +156,7 @@ func TestInstallIfNeeded(t *testing.T) {
 	defer cleanup()
 	out := o.Out.(*bytes.Buffer)
 
-	envoyPath, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, globals.CurrentPlatform, version.LastKnownEnvoy)
+	envoyPath, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, version.LastKnownEnvoy)
 	require.NoError(t, e)
 	require.Equal(t, o.EnvoyPath, envoyPath)
 	require.FileExists(t, envoyPath)
@@ -164,7 +165,7 @@ func TestInstallIfNeeded(t *testing.T) {
 	versionDir := strings.Replace(envoyPath, binEnvoy, "", 1)
 	f, err := os.Stat(versionDir)
 	require.NoError(t, err)
-	require.Equal(t, f.ModTime().Format("2006-01-02"), string(test.FakeReleaseDate))
+	require.Equal(t, f.ModTime().UTC().Format("2006-01-02"), string(test.FakeReleaseDate))
 
 	require.Equal(t, fmt.Sprintln("downloading", o.tarballURL), out.String())
 }
@@ -174,11 +175,13 @@ func TestInstallIfNeeded_NotFound(t *testing.T) {
 	defer cleanup()
 
 	t.Run("unknown version", func(t *testing.T) {
-		_, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, "darwin/amd64", "1.1.1")
+		o.Platform = "darwin/amd64"
+		_, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, "1.1.1")
 		require.EqualError(t, e, `couldn't find version "1.1.1" for platform "darwin/amd64"`)
 	})
 	t.Run("unknown platform", func(t *testing.T) {
-		_, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, "solaris/amd64", version.LastKnownEnvoy)
+		o.Platform = "solaris/amd64"
+		_, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, version.LastKnownEnvoy)
 		require.EqualError(t, e, fmt.Sprintf(`couldn't find version "%s" for platform "solaris/amd64"`, version.LastKnownEnvoy))
 	})
 }
@@ -194,7 +197,7 @@ func TestInstallIfNeeded_AlreadyExists(t *testing.T) {
 	envoyStat, err := os.Stat(o.EnvoyPath)
 	require.NoError(t, err)
 
-	envoyPath, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, globals.CurrentPlatform, version.LastKnownEnvoy)
+	envoyPath, e := InstallIfNeeded(o.ctx, &o.GlobalOpts, version.LastKnownEnvoy)
 	require.NoError(t, e)
 	require.Equal(t, fmt.Sprintln(version.LastKnownEnvoy, "is already downloaded"), out.String())
 
@@ -257,6 +260,7 @@ func setupInstallTest(t *testing.T) (*installTest, func()) {
 				HomeDir:          tempDir,
 				EnvoyVersionsURL: versionsServer.URL + "/envoy-versions.json",
 				Out:              new(bytes.Buffer),
+				Platform:         globals.DefaultPlatform,
 				RunOpts: globals.RunOpts{
 					EnvoyPath: filepath.Join(tempDir, "versions", string(version.LastKnownEnvoy), binEnvoy),
 				},
diff --git a/internal/globals/globals.go b/internal/globals/globals.go
index 03718ddb..b96baf93 100644
--- a/internal/globals/globals.go
+++ b/internal/globals/globals.go
@@ -58,6 +58,8 @@ type GlobalOpts struct {
 	HomeDir string
 	// Out is where status messages are written. Defaults to os.Stdout
 	Out io.Writer
+	// The platform to target for the Envoy install.
+	Platform version.Platform
 }
 
 const (
@@ -65,11 +67,11 @@ const (
 	DefaultHomeDir = "${HOME}/.func-e"
 	// DefaultEnvoyVersionsURL is the default value for GlobalOpts.EnvoyVersionsURL
 	DefaultEnvoyVersionsURL = "https://archive.tetratelabs.io/envoy/envoy-versions.json"
+	// DefaultPlatform is the current platform of the host machine
+	DefaultPlatform = version.Platform(runtime.GOOS + "/" + runtime.GOARCH)
 )
 
 var (
 	// EnvoyVersionPattern is used to validate versions and is the same pattern as release-versions-schema.json.
 	EnvoyVersionPattern = regexp.MustCompile(`^[1-9][0-9]*\.[0-9]+\.[0-9]+(_debug)?$`)
-	// CurrentPlatform is the platform of the current process. This is used as a key in EnvoyVersion.Tarballs.
-	CurrentPlatform = version.Platform(runtime.GOOS + "/" + runtime.GOARCH)
 )