diff --git a/libcutils/fs_config.cpp b/libcutils/fs_config.cpp
index a2dd677..2b3443f 100644
--- a/libcutils/fs_config.cpp
+++ b/libcutils/fs_config.cpp
@@ -92,6 +92,9 @@
     { 00755, AID_ROOT,         AID_ROOT,         0, 0 },
     // clang-format on
 };
+#ifndef __ANDROID_VNDK__
+auto __for_testing_only__android_dirs = android_dirs;
+#endif
 
 // Rules for files.
 // These rules are applied based on "first match", so they
@@ -238,6 +241,9 @@
     { 00644, AID_ROOT,      AID_ROOT,      0, 0 },
     // clang-format on
 };
+#ifndef __ANDROID_VNDK__
+auto __for_testing_only__android_files = android_files;
+#endif
 
 static size_t strip(const char* path, size_t len, const char suffix[]) {
     if (len < strlen(suffix)) return len;
diff --git a/libcutils/tests/Android.bp b/libcutils/tests/Android.bp
index a0b1d7b..7884190 100644
--- a/libcutils/tests/Android.bp
+++ b/libcutils/tests/Android.bp
@@ -27,7 +27,8 @@
                 "test_str_parms.cpp",
                 "android_get_control_socket_test.cpp",
                 "android_get_control_file_test.cpp",
-                "multiuser_test.cpp"
+                "multiuser_test.cpp",
+                "fs_config.cpp",
             ],
         },
 
diff --git a/libcutils/tests/fs_config.cpp b/libcutils/tests/fs_config.cpp
new file mode 100644
index 0000000..3917a0b
--- /dev/null
+++ b/libcutils/tests/fs_config.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2017 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 <string>
+
+#include <gtest/gtest.h>
+
+#include <android-base/strings.h>
+
+#include <private/android_filesystem_config.h>
+
+extern const struct fs_path_config* __for_testing_only__android_dirs;
+extern const struct fs_path_config* __for_testing_only__android_files;
+
+static void check_one(const struct fs_path_config* paths, const std::string& prefix,
+                      const std::string& alternate) {
+    for (size_t idx = 0; paths[idx].prefix; ++idx) {
+        std::string path(paths[idx].prefix);
+        if (android::base::StartsWith(path, prefix.c_str())) {
+            path = alternate + path.substr(prefix.length());
+            size_t second;
+            for (second = 0; paths[second].prefix; ++second) {
+                if (path == paths[second].prefix) break;
+            }
+            if (!paths[second].prefix) {
+                // guaranteed to fail expectations, trigger test failure with
+                // a message that reports the violation as an inequality.
+                EXPECT_STREQ((prefix + path.substr(alternate.length())).c_str(), path.c_str());
+            }
+        }
+    }
+}
+
+static void check_two(const struct fs_path_config* paths, const std::string& prefix) {
+    ASSERT_FALSE(paths == nullptr);
+    std::string alternate = "system/" + prefix;
+    check_one(paths, prefix, alternate);
+    check_one(paths, alternate, prefix);
+}
+
+TEST(fs_config, vendor_dirs_alias) {
+    check_two(__for_testing_only__android_dirs, "vendor/");
+}
+
+TEST(fs_config, vendor_files_alias) {
+    check_two(__for_testing_only__android_files, "vendor/");
+}
+
+TEST(fs_config, oem_dirs_alias) {
+    check_two(__for_testing_only__android_dirs, "oem/");
+}
+
+TEST(fs_config, oem_files_alias) {
+    check_two(__for_testing_only__android_files, "oem/");
+}
+
+TEST(fs_config, odm_dirs_alias) {
+    check_two(__for_testing_only__android_dirs, "odm/");
+}
+
+TEST(fs_config, odm_files_alias) {
+    check_two(__for_testing_only__android_files, "odm/");
+}