diff --git a/libvendorsupport/Android.bp b/libvendorsupport/Android.bp
index e87959e..a22737c 100644
--- a/libvendorsupport/Android.bp
+++ b/libvendorsupport/Android.bp
@@ -23,7 +23,7 @@
     llndk: {
         symbol_file: "libvendorsupport.map.txt",
     },
-    srcs: ["version_props.c"],
+    srcs: ["version_props.cpp"],
     cflags: [
         "-Wall",
         "-Werror",
@@ -32,6 +32,7 @@
     export_include_dirs: ["include"],
     shared_libs: [
         "liblog",
+        "libbase",
     ],
 }
 
diff --git a/libvendorsupport/include/vendorsupport/api_level.h b/libvendorsupport/include/vendorsupport/api_level.h
index d365075..3427bc6 100644
--- a/libvendorsupport/include/vendorsupport/api_level.h
+++ b/libvendorsupport/include/vendorsupport/api_level.h
@@ -44,4 +44,22 @@
  */
 int AVendorSupport_getSdkApiLevelOf(int vendorApiLevel);
 
+#if !defined(__ANDROID_VENDOR__)
+/**
+ * @brief Provide vendor API level to system modules.
+ *
+ * @details
+ * Before deprecating VNDK, system modules read ro.vndk.version to find the
+ * API level that vendor image had implemented. With the VNDK deprecation, this
+ * must be replaced with ro.board.api_level. However, there still are devices
+ * keeping old vendor partitions with the new system upgraded. In this case, the
+ * VNDK version can be used as before.
+ * This API is for platform only.
+ *
+ * @return ro.vndk.version if exist. Otherwise fallback to ro.board.api_level.
+ * 0 if none of these properties are found. This is unexpected, though.
+ */
+int AVendorSupport_getVendorApiLevel();
+#endif  // __ANDROID_VENDOR__
+
 __END_DECLS
diff --git a/libvendorsupport/version_props.c b/libvendorsupport/version_props.cpp
similarity index 79%
rename from libvendorsupport/version_props.c
rename to libvendorsupport/version_props.cpp
index 835828c..ecba899 100644
--- a/libvendorsupport/version_props.c
+++ b/libvendorsupport/version_props.cpp
@@ -16,6 +16,10 @@
 
 #include <log/log.h>
 
+#if !defined(__ANDROID_VENDOR__)
+#include <android-base/properties.h>
+#endif
+
 int AVendorSupport_getVendorApiLevelOf(int sdkApiLevel) {
     if (sdkApiLevel < __ANDROID_API_V__) {
         return sdkApiLevel;
@@ -39,3 +43,13 @@
     ALOGE("Unexpected vendor api level: %d", vendorApiLevel);
     return __INVALID_API_LEVEL;
 }
+
+#if !defined(__ANDROID_VENDOR__)
+int AVendorSupport_getVendorApiLevel() {
+    int vendorApiLevel = android::base::GetIntProperty("ro.vndk.version", 0);
+    if (vendorApiLevel) {
+        return vendorApiLevel;
+    }
+    return android::base::GetIntProperty("ro.board.api_level", 0);
+}
+#endif  // __ANDROID_VENDOR__