diff --git a/tests/Android.bp b/tests/Android.bp
index 00f2856..b504fa1 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -167,6 +167,7 @@
         "sys_ttydefaults_test.cpp",
         "sys_types_test.cpp",
         "sys_uio_test.cpp",
+        "sys_un_test.cpp",
         "sys_vfs_test.cpp",
         "sys_xattr_test.cpp",
         "system_properties_test.cpp",
diff --git a/tests/sys_un_test.cpp b/tests/sys_un_test.cpp
new file mode 100644
index 0000000..08a4d0f
--- /dev/null
+++ b/tests/sys_un_test.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <sys/un.h>
+
+#include <string.h>
+#include <gtest/gtest.h>
+
+TEST(sys_un, SUN_LEN_macro) {
+  sockaddr_un sun = {};
+  sun.sun_family = 1;
+  strcpy(sun.sun_path, "hello");
+  ASSERT_EQ(2U + strlen("hello"), SUN_LEN(&sun));
+}