diff --git a/util/testutil/integration/run.go b/util/testutil/integration/run.go
index 3b009558bbda8..ae473df32e075 100644
--- a/util/testutil/integration/run.go
+++ b/util/testutil/integration/run.go
@@ -57,8 +57,8 @@ type Sandbox interface {
 
 // BackendConfig is used to configure backends created by a worker.
 type BackendConfig struct {
-	Logs       map[string]*bytes.Buffer
-	ConfigFile string
+	Logs         map[string]*bytes.Buffer
+	DaemonConfig []ConfigUpdater
 }
 
 type Worker interface {
@@ -303,7 +303,21 @@ mirrors=["%s"]
 `, in, mc)
 }
 
-func writeConfig(updaters []ConfigUpdater) (string, error) {
+func WithOTELSocketPath(socketPath string) ConfigUpdater {
+	return otelSocketPath(socketPath)
+}
+
+type otelSocketPath string
+
+func (osp otelSocketPath) UpdateConfigFile(in string) string {
+	return fmt.Sprintf(`%s
+
+[otel]
+  socketPath = %q
+`, in, osp)
+}
+
+func WriteConfig(updaters []ConfigUpdater) (string, error) {
 	tmpdir, err := os.MkdirTemp("", "bktest_config")
 	if err != nil {
 		return "", err
@@ -320,7 +334,7 @@ func writeConfig(updaters []ConfigUpdater) (string, error) {
 	if err := os.WriteFile(filepath.Join(tmpdir, buildkitdConfigFile), []byte(s), 0644); err != nil {
 		return "", err
 	}
-	return tmpdir, nil
+	return filepath.Join(tmpdir, buildkitdConfigFile), nil
 }
 
 func runMirror(t *testing.T, mirroredImages map[string]string) (host string, _ func() error, err error) {
diff --git a/util/testutil/integration/sandbox.go b/util/testutil/integration/sandbox.go
index 593b52e8ef050..d7f1dfff2734f 100644
--- a/util/testutil/integration/sandbox.go
+++ b/util/testutil/integration/sandbox.go
@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
-	"path/filepath"
 	"strings"
 	"testing"
 
@@ -78,15 +77,14 @@ func newSandbox(ctx context.Context, w Worker, mirror string, mv matrixValue) (s
 		Logs: make(map[string]*bytes.Buffer),
 	}
 
-	var upt []ConfigUpdater
 	for _, v := range mv.values {
 		if u, ok := v.value.(ConfigUpdater); ok {
-			upt = append(upt, u)
+			cfg.DaemonConfig = append(cfg.DaemonConfig, u)
 		}
 	}
 
 	if mirror != "" {
-		upt = append(upt, withMirrorConfig(mirror))
+		cfg.DaemonConfig = append(cfg.DaemonConfig, withMirrorConfig(mirror))
 	}
 
 	deferF := &MultiCloser{}
@@ -99,17 +97,6 @@ func newSandbox(ctx context.Context, w Worker, mirror string, mv matrixValue) (s
 		}
 	}()
 
-	if len(upt) > 0 {
-		dir, err := writeConfig(upt)
-		if err != nil {
-			return nil, nil, err
-		}
-		deferF.Append(func() error {
-			return os.RemoveAll(dir)
-		})
-		cfg.ConfigFile = filepath.Join(dir, buildkitdConfigFile)
-	}
-
 	b, closer, err := w.New(ctx, cfg)
 	if err != nil {
 		return nil, nil, err
diff --git a/util/testutil/workers/dockerd.go b/util/testutil/workers/dockerd.go
index 7ed0d6f36e06a..41622d84d8f69 100644
--- a/util/testutil/workers/dockerd.go
+++ b/util/testutil/workers/dockerd.go
@@ -76,9 +76,27 @@ func (c Moby) New(ctx context.Context, cfg *integration.BackendConfig) (b integr
 		return nil, nil, err
 	}
 
-	bkcfg, err := config.LoadFile(cfg.ConfigFile)
+	deferF := &integration.MultiCloser{}
+	cl = deferF.F()
+
+	defer func() {
+		if err != nil {
+			deferF.F()()
+			cl = nil
+		}
+	}()
+
+	cfgFile, err := integration.WriteConfig(cfg.DaemonConfig)
 	if err != nil {
-		return nil, nil, errors.Wrapf(err, "failed to load buildkit config file %s", cfg.ConfigFile)
+		return nil, nil, err
+	}
+	deferF.Append(func() error {
+		return os.RemoveAll(filepath.Dir(cfgFile))
+	})
+
+	bkcfg, err := config.LoadFile(cfgFile)
+	if err != nil {
+		return nil, nil, errors.Wrapf(err, "failed to load buildkit config file %s", cfgFile)
 	}
 
 	dcfg := dockerd.Config{
@@ -107,16 +125,6 @@ func (c Moby) New(ctx context.Context, cfg *integration.BackendConfig) (b integr
 		return nil, nil, errors.Wrapf(err, "failed to marshal dockerd config")
 	}
 
-	deferF := &integration.MultiCloser{}
-	cl = deferF.F()
-
-	defer func() {
-		if err != nil {
-			deferF.F()()
-			cl = nil
-		}
-	}()
-
 	var proxyGroup errgroup.Group
 	deferF.Append(proxyGroup.Wait)
 
diff --git a/util/testutil/workers/util.go b/util/testutil/workers/util.go
index f01bdca670be8..c7611c7f59d3d 100644
--- a/util/testutil/workers/util.go
+++ b/util/testutil/workers/util.go
@@ -32,10 +32,6 @@ func runBuildkitd(ctx context.Context, conf *integration.BackendConfig, args []s
 		}
 	}()
 
-	if conf.ConfigFile != "" {
-		args = append(args, "--config="+conf.ConfigFile)
-	}
-
 	tmpdir, err := os.MkdirTemp("", "bktest_buildkitd")
 	if err != nil {
 		return "", nil, err
@@ -49,12 +45,20 @@ func runBuildkitd(ctx context.Context, conf *integration.BackendConfig, args []s
 	if err := os.Chown(filepath.Join(tmpdir, "tmp"), uid, gid); err != nil {
 		return "", nil, err
 	}
-
 	deferF.Append(func() error { return os.RemoveAll(tmpdir) })
 
+	cfgfile, err := integration.WriteConfig(append(conf.DaemonConfig, integration.WithOTELSocketPath(getTraceSocketPath(tmpdir))))
+	if err != nil {
+		return "", nil, err
+	}
+	deferF.Append(func() error {
+		return os.RemoveAll(filepath.Dir(cfgfile))
+	})
+	args = append(args, "--config="+cfgfile)
+
 	address = getBuildkitdAddr(tmpdir)
 
-	args = append(args, "--root", tmpdir, "--addr", address, "--otel-socket-path", getTraceSocketPath(tmpdir), "--debug")
+	args = append(args, "--root", tmpdir, "--addr", address, "--debug")
 	cmd := exec.Command(args[0], args[1:]...) //nolint:gosec // test utility
 	cmd.Env = append(os.Environ(), "BUILDKIT_DEBUG_EXEC_OUTPUT=1", "BUILDKIT_DEBUG_PANIC_ON_ERROR=1", "TMPDIR="+filepath.Join(tmpdir, "tmp"))
 	cmd.Env = append(cmd.Env, extraEnv...)