diff --git a/cmd/lattice/cmd.go b/cmd/lattice/cmd.go
index d4d1ddf..bc26bef 100644
--- a/cmd/lattice/cmd.go
+++ b/cmd/lattice/cmd.go
@@ -121,7 +121,7 @@ func command(_ context.Context, opt *option) error {
 	}
 	out := Stdout
 	if opt.output != "" {
-		f, err := os.OpenFile(opt.output, os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o666)
+		f, err := os.OpenFile(opt.output, os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o600)
 		if err != nil {
 			return err
 		}
diff --git a/kagome_test.go b/kagome_test.go
index 12045f2..0872db0 100644
--- a/kagome_test.go
+++ b/kagome_test.go
@@ -38,7 +38,7 @@ func TestKagomeTokenizerGolden(t *testing.T) {
 	}
 	defer golden.Close()
 
-	dump, err := os.OpenFile(dumpText, os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o666)
+	dump, err := os.OpenFile(dumpText, os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o600)
 	if err != nil {
 		t.Fatalf("unexpected error, %v", err)
 	}