diff --git a/bluetooth/1.0/default/test/bluetooth_address_test.cc b/bluetooth/1.0/default/test/bluetooth_address_test.cc
index e60729e..2c8dbe5 100644
--- a/bluetooth/1.0/default/test/bluetooth_address_test.cc
+++ b/bluetooth/1.0/default/test/bluetooth_address_test.cc
@@ -56,7 +56,7 @@
 
 void BluetoothAddressTest::FileWriteString(const char* path,
                                            const char* string) {
-  int fd = open(path, O_CREAT | O_RDWR);
+  int fd = open(path, O_CREAT | O_RDWR, 0600);
   EXPECT_TRUE(fd > 0) << "err = " << strerror(errno);
 
   size_t length = strlen(string);