diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 79d9a23..c065cd6 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -838,7 +838,7 @@
 
     private void addInterfaceToNetwork(final int netId, @NonNull final String ifaceName) {
         try {
-            if (null != mRoutingCoordinator.value) {
+            if (SdkLevel.isAtLeastS() && null != mRoutingCoordinator.value) {
                 // TODO : remove this call in favor of using the LocalNetworkConfiguration
                 // correctly, which will let ConnectivityService do it automatically.
                 mRoutingCoordinator.value.addInterfaceToNetwork(netId, ifaceName);
@@ -852,7 +852,7 @@
 
     private void addInterfaceForward(@NonNull final String fromIface,
             @NonNull final String toIface) throws ServiceSpecificException, RemoteException {
-        if (null != mRoutingCoordinator.value) {
+        if (SdkLevel.isAtLeastS() && null != mRoutingCoordinator.value) {
             mRoutingCoordinator.value.addInterfaceForward(fromIface, toIface);
         } else {
             mNetd.tetherAddForward(fromIface, toIface);
@@ -862,7 +862,7 @@
 
     private void removeInterfaceForward(@NonNull final String fromIface,
             @NonNull final String toIface) {
-        if (null != mRoutingCoordinator.value) {
+        if (SdkLevel.isAtLeastS() && null != mRoutingCoordinator.value) {
             try {
                 mRoutingCoordinator.value.removeInterfaceForward(fromIface, toIface);
             } catch (ServiceSpecificException e) {
diff --git a/Tethering/src/com/android/networkstack/tethering/OffloadHalAidlImpl.java b/Tethering/src/com/android/networkstack/tethering/OffloadHalAidlImpl.java
index e7dc757..9ef0f45 100644
--- a/Tethering/src/com/android/networkstack/tethering/OffloadHalAidlImpl.java
+++ b/Tethering/src/com/android/networkstack/tethering/OffloadHalAidlImpl.java
@@ -19,18 +19,21 @@
 import static com.android.networkstack.tethering.OffloadHardwareInterface.OFFLOAD_HAL_VERSION_AIDL;
 
 import android.annotation.NonNull;
+import android.annotation.TargetApi;
 import android.hardware.tetheroffload.ForwardedStats;
 import android.hardware.tetheroffload.IOffload;
 import android.hardware.tetheroffload.ITetheringOffloadCallback;
 import android.hardware.tetheroffload.NatTimeoutUpdate;
 import android.hardware.tetheroffload.NetworkProtocol;
 import android.hardware.tetheroffload.OffloadCallbackEvent;
+import android.os.Build;
 import android.os.Handler;
 import android.os.NativeHandle;
 import android.os.ParcelFileDescriptor;
 import android.os.ServiceManager;
 import android.system.OsConstants;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.SharedLog;
 import com.android.networkstack.tethering.OffloadHardwareInterface.OffloadHalCallback;
@@ -40,6 +43,7 @@
 /**
  * The implementation of IOffloadHal which based on Stable AIDL interface
  */
+@TargetApi(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
 public class OffloadHalAidlImpl implements IOffloadHal {
     private static final String TAG = OffloadHalAidlImpl.class.getSimpleName();
     private static final String HAL_INSTANCE_NAME = IOffload.DESCRIPTOR + "/default";
@@ -52,6 +56,7 @@
 
     private TetheringOffloadCallback mTetheringOffloadCallback;
 
+    @VisibleForTesting
     public OffloadHalAidlImpl(int version, @NonNull IOffload offload, @NonNull Handler handler,
             @NonNull SharedLog log) {
         mOffloadVersion = version;