diff --git a/test/sandbox/assert.go b/test/internal/sandbox/assert.go
similarity index 100%
rename from test/sandbox/assert.go
rename to test/internal/sandbox/assert.go
diff --git a/test/sandbox/assert_test.go b/test/internal/sandbox/assert_test.go
similarity index 100%
rename from test/sandbox/assert_test.go
rename to test/internal/sandbox/assert_test.go
diff --git a/test/sandbox/fs.go b/test/internal/sandbox/fs.go
similarity index 100%
rename from test/sandbox/fs.go
rename to test/internal/sandbox/fs.go
diff --git a/test/sandbox/fs_test.go b/test/internal/sandbox/fs_test.go
similarity index 98%
rename from test/sandbox/fs_test.go
rename to test/internal/sandbox/fs_test.go
index 8dd920b..a7813ee 100644
--- a/test/sandbox/fs_test.go
+++ b/test/internal/sandbox/fs_test.go
@@ -10,7 +10,7 @@ import (
 	"testing"
 	"testing/fstest"
 
-	"hakurei.app/test/sandbox"
+	"hakurei.app/test/internal/sandbox"
 )
 
 var (
diff --git a/test/sandbox/mount.go b/test/internal/sandbox/mount.go
similarity index 100%
rename from test/sandbox/mount.go
rename to test/internal/sandbox/mount.go
diff --git a/test/sandbox/mount_test.go b/test/internal/sandbox/mount_test.go
similarity index 99%
rename from test/sandbox/mount_test.go
rename to test/internal/sandbox/mount_test.go
index 7d6b0df..65bcec4 100644
--- a/test/sandbox/mount_test.go
+++ b/test/internal/sandbox/mount_test.go
@@ -7,7 +7,7 @@ import (
 	"path"
 	"testing"
 
-	"hakurei.app/test/sandbox"
+	"hakurei.app/test/internal/sandbox"
 )
 
 func TestMountinfo(t *testing.T) {
diff --git a/test/sandbox/ptrace.go b/test/internal/sandbox/ptrace.go
similarity index 100%
rename from test/sandbox/ptrace.go
rename to test/internal/sandbox/ptrace.go
diff --git a/test/sandbox/seccomp.go b/test/internal/sandbox/seccomp.go
similarity index 100%
rename from test/sandbox/seccomp.go
rename to test/internal/sandbox/seccomp.go
diff --git a/test/sandbox/tool/main.go b/test/sandbox/tool/main.go
index ef3325d..889142d 100644
--- a/test/sandbox/tool/main.go
+++ b/test/sandbox/tool/main.go
@@ -12,7 +12,7 @@ import (
 	"strings"
 	"syscall"
 
-	"hakurei.app/test/sandbox"
+	"hakurei.app/test/internal/sandbox"
 )
 
 var (