diff --git a/container/container.go b/container/container.go
index ecfb94c..a10e610 100644
--- a/container/container.go
+++ b/container/container.go
@@ -35,9 +35,6 @@ type (
 		// with behaviour identical to its [exec.Cmd] counterpart.
 		ExtraFiles []*os.File
 
-		// Custom [exec.Cmd] initialisation function.
-		CommandContext func(ctx context.Context) (cmd *exec.Cmd)
-
 		// param encoder for shim and init
 		setup *gob.Encoder
 		// cancels cmd
@@ -122,13 +119,8 @@ func (p *Container) Start() error {
 		p.SeccompPresets |= seccomp.PresetDenyTTY
 	}
 
-	if p.CommandContext != nil {
-		p.cmd = p.CommandContext(ctx)
-	} else {
-		p.cmd = exec.CommandContext(ctx, MustExecutable())
-		p.cmd.Args = []string{"init"}
-	}
-
+	p.cmd = exec.CommandContext(ctx, MustExecutable())
+	p.cmd.Args = []string{"init"}
 	p.cmd.Stdin, p.cmd.Stdout, p.cmd.Stderr = p.Stdin, p.Stdout, p.Stderr
 	p.cmd.WaitDelay = p.WaitDelay
 	if p.Cancel != nil {
diff --git a/container/container_test.go b/container/container_test.go
index 4ded1fb..8024319 100644
--- a/container/container_test.go
+++ b/container/container_test.go
@@ -6,7 +6,6 @@ import (
 	"encoding/gob"
 	"log"
 	"os"
-	"os/exec"
 	"strings"
 	"syscall"
 	"testing"
@@ -26,6 +25,11 @@ const (
 	ignoreV = -1
 )
 
+func TestMain(m *testing.M) {
+	container.TryArgv0(hlog.Output{}, hlog.Prepare, internal.InstallOutput)
+	os.Exit(m.Run())
+}
+
 func TestContainer(t *testing.T) {
 	{
 		oldVerbose := hlog.Load()
@@ -96,7 +100,6 @@ func TestContainer(t *testing.T) {
 			c.Uid = 1000
 			c.Gid = 100
 			c.Hostname = tc.host
-			c.CommandContext = commandContext
 			c.Stdout, c.Stderr = os.Stdout, os.Stderr
 			c.Ops = tc.ops
 			c.SeccompRules = tc.rules
@@ -121,11 +124,7 @@ func TestContainer(t *testing.T) {
 				Place("/etc/hostname", []byte(c.Args[5]))
 			// in case test has cgo enabled
 			var libPaths []string
-			if entries, err := ldd.ExecFilter(ctx,
-				commandContext,
-				func(v []byte) []byte {
-					return bytes.SplitN(v, []byte("TestHelperInit\n"), 2)[1]
-				}, os.Args[0]); err != nil {
+			if entries, err := ldd.Exec(ctx, os.Args[0]); err != nil {
 				log.Fatalf("ldd: %v", err)
 			} else {
 				libPaths = ldd.Path(entries)
@@ -197,14 +196,6 @@ func TestContainerString(t *testing.T) {
 	}
 }
 
-func TestHelperInit(t *testing.T) {
-	if len(os.Args) != 5 || os.Args[4] != "init" {
-		return
-	}
-	container.SetOutput(hlog.Output{})
-	container.Init(hlog.Prepare, internal.InstallOutput)
-}
-
 func TestHelperCheckContainer(t *testing.T) {
 	if len(os.Args) != 6 || os.Args[4] != "check" {
 		return
@@ -274,8 +265,3 @@ func TestHelperCheckContainer(t *testing.T) {
 		}
 	})
 }
-
-func commandContext(ctx context.Context) *exec.Cmd {
-	return exec.CommandContext(ctx, os.Args[0], "-test.v",
-		"-test.run=TestHelperInit", "--", "init")
-}
diff --git a/helper/container_test.go b/helper/container_test.go
index 71c25bd..f5dc1aa 100644
--- a/helper/container_test.go
+++ b/helper/container_test.go
@@ -4,13 +4,10 @@ import (
 	"context"
 	"io"
 	"os"
-	"os/exec"
 	"testing"
 
 	"hakurei.app/container"
 	"hakurei.app/helper"
-	"hakurei.app/internal"
-	"hakurei.app/internal/hlog"
 )
 
 func TestContainer(t *testing.T) {
@@ -36,20 +33,8 @@ func TestContainer(t *testing.T) {
 		testHelper(t, func(ctx context.Context, setOutput func(stdoutP, stderrP *io.Writer), stat bool) helper.Helper {
 			return helper.New(ctx, os.Args[0], argsWt, stat, argF, func(z *container.Container) {
 				setOutput(&z.Stdout, &z.Stderr)
-				z.CommandContext = func(ctx context.Context) (cmd *exec.Cmd) {
-					return exec.CommandContext(ctx, os.Args[0], "-test.v",
-						"-test.run=TestHelperInit", "--", "init")
-				}
 				z.Bind("/", "/", 0).Proc("/proc").Dev("/dev")
 			}, nil)
 		})
 	})
 }
-
-func TestHelperInit(t *testing.T) {
-	if len(os.Args) != 5 || os.Args[4] != "init" {
-		return
-	}
-	container.SetOutput(hlog.Output{})
-	container.Init(hlog.Prepare, func(bool) { internal.InstallOutput(false) })
-}
diff --git a/helper/helper_test.go b/helper/helper_test.go
index cc6f892..ef4b6bc 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -38,7 +38,6 @@ func argF(argsFd, statFd int) []string {
 
 func argFChecked(argsFd, statFd int) (args []string) {
 	args = make([]string, 0, 6)
-	args = append(args, "-test.run=TestHelperStub", "--")
 	if argsFd > -1 {
 		args = append(args, "--args", strconv.Itoa(argsFd))
 	}
diff --git a/helper/stub.go b/helper/stub.go
index bd0e1b5..852930f 100644
--- a/helper/stub.go
+++ b/helper/stub.go
@@ -25,7 +25,7 @@ func InternalHelperStub() {
 		sp = v
 	}
 
-	genericStub(flagRestoreFiles(3, ap, sp))
+	genericStub(flagRestoreFiles(1, ap, sp))
 
 	os.Exit(0)
 }
diff --git a/helper/stub_test.go b/helper/stub_test.go
index e496f14..dc057ac 100644
--- a/helper/stub_test.go
+++ b/helper/stub_test.go
@@ -1,9 +1,17 @@
 package helper_test
 
 import (
+	"os"
 	"testing"
 
+	"hakurei.app/container"
 	"hakurei.app/helper"
+	"hakurei.app/internal"
+	"hakurei.app/internal/hlog"
 )
 
-func TestHelperStub(t *testing.T) { helper.InternalHelperStub() }
+func TestMain(m *testing.M) {
+	container.TryArgv0(hlog.Output{}, hlog.Prepare, internal.InstallOutput)
+	helper.InternalHelperStub()
+	os.Exit(m.Run())
+}
diff --git a/ldd/exec.go b/ldd/exec.go
index 2544050..c159368 100644
--- a/ldd/exec.go
+++ b/ldd/exec.go
@@ -5,7 +5,6 @@ import (
 	"context"
 	"io"
 	"os"
-	"os/exec"
 	"time"
 
 	"hakurei.app/container"
@@ -19,16 +18,10 @@ var (
 	msgStaticGlibc = []byte("not a dynamic executable")
 )
 
-func Exec(ctx context.Context, p string) ([]*Entry, error) { return ExecFilter(ctx, nil, nil, p) }
-
-func ExecFilter(ctx context.Context,
-	commandContext func(context.Context) *exec.Cmd,
-	f func([]byte) []byte,
-	p string) ([]*Entry, error) {
+func Exec(ctx context.Context, p string) ([]*Entry, error) {
 	c, cancel := context.WithTimeout(ctx, lddTimeout)
 	defer cancel()
 	z := container.New(c, "ldd", p)
-	z.CommandContext = commandContext
 	z.Hostname = "hakurei-ldd"
 	z.SeccompFlags |= seccomp.AllowMultiarch
 	z.SeccompPresets |= seccomp.PresetStrict
@@ -54,8 +47,5 @@ func ExecFilter(ctx context.Context,
 	}
 
 	v := stdout.Bytes()
-	if f != nil {
-		v = f(v)
-	}
 	return Parse(v)
 }
diff --git a/system/dbus/dbus_test.go b/system/dbus/dbus_test.go
index 919e13a..213bb37 100644
--- a/system/dbus/dbus_test.go
+++ b/system/dbus/dbus_test.go
@@ -1,22 +1,17 @@
 package dbus_test
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
 	"io"
 	"os"
-	"os/exec"
 	"strings"
 	"syscall"
 	"testing"
 	"time"
 
-	"hakurei.app/container"
 	"hakurei.app/helper"
-	"hakurei.app/internal"
-	"hakurei.app/internal/hlog"
 	"hakurei.app/system/dbus"
 )
 
@@ -64,20 +59,23 @@ func TestFinalise(t *testing.T) {
 }
 
 func TestProxyStartWaitCloseString(t *testing.T) {
-	oldWaitDelay := helper.WaitDelay
-	helper.WaitDelay = 16 * time.Second
-	t.Cleanup(func() { helper.WaitDelay = oldWaitDelay })
-
-	t.Run("sandbox", func(t *testing.T) {
-		proxyName := dbus.ProxyName
-		dbus.ProxyName = os.Args[0]
-		t.Cleanup(func() { dbus.ProxyName = proxyName })
-		testProxyFinaliseStartWaitCloseString(t, true)
-	})
+	t.Run("sandbox", func(t *testing.T) { testProxyFinaliseStartWaitCloseString(t, true) })
 	t.Run("direct", func(t *testing.T) { testProxyFinaliseStartWaitCloseString(t, false) })
 }
 
 func testProxyFinaliseStartWaitCloseString(t *testing.T, useSandbox bool) {
+	{
+		oldWaitDelay := helper.WaitDelay
+		helper.WaitDelay = 16 * time.Second
+		t.Cleanup(func() { helper.WaitDelay = oldWaitDelay })
+	}
+
+	{
+		proxyName := dbus.ProxyName
+		dbus.ProxyName = os.Args[0]
+		t.Cleanup(func() { dbus.ProxyName = proxyName })
+	}
+
 	var p *dbus.Proxy
 
 	t.Run("string for nil proxy", func(t *testing.T) {
@@ -122,35 +120,12 @@ func testProxyFinaliseStartWaitCloseString(t *testing.T, useSandbox bool) {
 
 			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
 			defer cancel()
-			if !useSandbox {
-				p = dbus.NewDirect(ctx, final, nil)
-			} else {
-				p = dbus.New(ctx, final, nil)
-			}
-
-			p.CommandContext = func(ctx context.Context) (cmd *exec.Cmd) {
-				return exec.CommandContext(ctx, os.Args[0], "-test.v",
-					"-test.run=TestHelperInit", "--", "init")
-			}
-			p.CmdF = func(v any) {
-				if useSandbox {
-					z := v.(*container.Container)
-					if z.Args[0] != dbus.ProxyName {
-						panic(fmt.Sprintf("unexpected argv0 %q", os.Args[0]))
-					}
-					z.Args = append([]string{os.Args[0], "-test.run=TestHelperStub", "--"}, z.Args[1:]...)
-				} else {
-					cmd := v.(*exec.Cmd)
-					if cmd.Args[0] != dbus.ProxyName {
-						panic(fmt.Sprintf("unexpected argv0 %q", os.Args[0]))
-					}
-					cmd.Err = nil
-					cmd.Path = os.Args[0]
-					cmd.Args = append([]string{os.Args[0], "-test.run=TestHelperStub", "--"}, cmd.Args[1:]...)
-				}
-			}
-			p.FilterF = func(v []byte) []byte { return bytes.SplitN(v, []byte("TestHelperInit\n"), 2)[1] }
 			output := new(strings.Builder)
+			if !useSandbox {
+				p = dbus.NewDirect(ctx, final, output)
+			} else {
+				p = dbus.New(ctx, final, output)
+			}
 
 			t.Run("invalid wait", func(t *testing.T) {
 				wantErr := "dbus: not started"
@@ -176,9 +151,9 @@ func testProxyFinaliseStartWaitCloseString(t *testing.T, useSandbox bool) {
 				}
 
 				t.Run("string", func(t *testing.T) {
-					wantSubstr := fmt.Sprintf("%s -test.run=TestHelperStub -- --args=3 --fd=4", os.Args[0])
+					wantSubstr := fmt.Sprintf("%s --args=3 --fd=4", os.Args[0])
 					if useSandbox {
-						wantSubstr = fmt.Sprintf(`argv: ["%s" "-test.run=TestHelperStub" "--" "--args=3" "--fd=4"], filter: true, rules: 0, flags: 0x1, presets: 0xf`, os.Args[0])
+						wantSubstr = fmt.Sprintf(`argv: ["%s" "--args=3" "--fd=4"], filter: true, rules: 0, flags: 0x1, presets: 0xf`, os.Args[0])
 					}
 					if got := p.String(); !strings.Contains(got, wantSubstr) {
 						t.Errorf("String: %q, want %q",
@@ -203,11 +178,3 @@ func testProxyFinaliseStartWaitCloseString(t *testing.T, useSandbox bool) {
 		})
 	}
 }
-
-func TestHelperInit(t *testing.T) {
-	if len(os.Args) != 5 || os.Args[4] != "init" {
-		return
-	}
-	container.SetOutput(hlog.Output{})
-	container.Init(hlog.Prepare, internal.InstallOutput)
-}
diff --git a/system/dbus/proc.go b/system/dbus/proc.go
index 879bc77..dfa42e2 100644
--- a/system/dbus/proc.go
+++ b/system/dbus/proc.go
@@ -36,9 +36,6 @@ func (p *Proxy) Start() error {
 
 	if !p.useSandbox {
 		p.helper = helper.NewDirect(ctx, p.name, p.final, true, argF, func(cmd *exec.Cmd) {
-			if p.CmdF != nil {
-				p.CmdF(cmd)
-			}
 			if p.output != nil {
 				cmd.Stdout, cmd.Stderr = p.output, p.output
 			}
@@ -56,7 +53,7 @@ func (p *Proxy) Start() error {
 		}
 
 		var libPaths []string
-		if entries, err := ldd.ExecFilter(ctx, p.CommandContext, p.FilterF, toolPath); err != nil {
+		if entries, err := ldd.Exec(ctx, toolPath); err != nil {
 			return err
 		} else {
 			libPaths = ldd.Path(entries)
@@ -69,15 +66,10 @@ func (p *Proxy) Start() error {
 				z.SeccompFlags |= seccomp.AllowMultiarch
 				z.SeccompPresets |= seccomp.PresetStrict
 				z.Hostname = "hakurei-dbus"
-				z.CommandContext = p.CommandContext
 				if p.output != nil {
 					z.Stdout, z.Stderr = p.output, p.output
 				}
 
-				if p.CmdF != nil {
-					p.CmdF(z)
-				}
-
 				// these lib paths are unpredictable, so mount them first so they cannot cover anything
 				for _, name := range libPaths {
 					z.Bind(name, name, 0)
diff --git a/system/dbus/proc_test.go b/system/dbus/proc_test.go
new file mode 100644
index 0000000..5e93ace
--- /dev/null
+++ b/system/dbus/proc_test.go
@@ -0,0 +1,17 @@
+package dbus_test
+
+import (
+	"os"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/helper"
+	"hakurei.app/internal"
+	"hakurei.app/internal/hlog"
+)
+
+func TestMain(m *testing.M) {
+	container.TryArgv0(hlog.Output{}, hlog.Prepare, internal.InstallOutput)
+	helper.InternalHelperStub()
+	os.Exit(m.Run())
+}
diff --git a/system/dbus/proxy.go b/system/dbus/proxy.go
index 8fed8f2..2f625f6 100644
--- a/system/dbus/proxy.go
+++ b/system/dbus/proxy.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"os/exec"
 	"sync"
 	"syscall"
 
@@ -37,10 +36,6 @@ type Proxy struct {
 	useSandbox bool
 
 	name string
-	CmdF func(any)
-
-	CommandContext func(ctx context.Context) (cmd *exec.Cmd)
-	FilterF        func([]byte) []byte
 
 	mu, pmu sync.RWMutex
 }
diff --git a/system/dbus/stub_test.go b/system/dbus/stub_test.go
deleted file mode 100644
index 7972539..0000000
--- a/system/dbus/stub_test.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package dbus_test
-
-import (
-	"testing"
-
-	"hakurei.app/helper"
-)
-
-func TestHelperStub(t *testing.T) { helper.InternalHelperStub() }