diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index c065cd66521df56939779aa5f9869c69458f9107..a8c840803b50e30257a6472b7971b7a70204b83e 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -33,7 +33,6 @@ import static android.system.OsConstants.RT_SCOPE_UNIVERSE;
 
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
 import static com.android.net.module.util.NetworkStackConstants.RFC7421_PREFIX_LENGTH;
-import static com.android.networkstack.tethering.TetheringConfiguration.USE_SYNC_SM;
 import static com.android.networkstack.tethering.UpstreamNetworkState.isVcnInterface;
 import static com.android.networkstack.tethering.util.PrefixUtils.asIpPrefix;
 import static com.android.networkstack.tethering.util.TetheringMessageBase.BASE_IPSERVER;
@@ -316,6 +315,7 @@ public class IpServer extends StateMachineShim {
 
     private final TetheringMetrics mTetheringMetrics;
     private final Handler mHandler;
+    private final boolean mIsSyncSM;
 
     // TODO: Add a dependency object to pass the data members or variables from the tethering
     // object. It helps to reduce the arguments of the constructor.
@@ -325,7 +325,7 @@ public class IpServer extends StateMachineShim {
             @Nullable LateSdk<RoutingCoordinatorManager> routingCoordinator, Callback callback,
             TetheringConfiguration config, PrivateAddressCoordinator addressCoordinator,
             TetheringMetrics tetheringMetrics, Dependencies deps) {
-        super(ifaceName, USE_SYNC_SM ? null : handler.getLooper());
+        super(ifaceName, config.isSyncSM() ? null : handler.getLooper());
         mHandler = handler;
         mLog = log.forSubComponent(ifaceName);
         mNetd = netd;
@@ -338,6 +338,7 @@ public class IpServer extends StateMachineShim {
         mLinkProperties = new LinkProperties();
         mUsingLegacyDhcp = config.useLegacyDhcpServer();
         mP2pLeasesSubnetPrefixLength = config.getP2pLeasesSubnetPrefixLength();
+        mIsSyncSM = config.isSyncSM();
         mPrivateAddressCoordinator = addressCoordinator;
         mDeps = deps;
         mTetheringMetrics = tetheringMetrics;
@@ -515,7 +516,7 @@ public class IpServer extends StateMachineShim {
 
         private void handleError() {
             mLastError = TETHER_ERROR_DHCPSERVER_ERROR;
-            if (USE_SYNC_SM) {
+            if (mIsSyncSM) {
                 sendMessage(CMD_SERVICE_FAILED_TO_START, TETHER_ERROR_DHCPSERVER_ERROR);
             } else {
                 sendMessageAtFrontOfQueueToAsyncSM(CMD_SERVICE_FAILED_TO_START,
@@ -1170,7 +1171,7 @@ public class IpServer extends StateMachineShim {
                 // in previous versions of the mainline module.
                 // TODO : remove sendMessageAtFrontOfQueueToAsyncSM after migrating to the Sync
                 // StateMachine.
-                if (USE_SYNC_SM) {
+                if (mIsSyncSM) {
                     sendSelfMessageToSyncSM(CMD_SERVICE_FAILED_TO_START, mLastError);
                 } else {
                     sendMessageAtFrontOfQueueToAsyncSM(CMD_SERVICE_FAILED_TO_START, mLastError);
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 0678525efd45befc9bdb3620dd47768293a872d9..d09183af2c367e88b42a6797eeafa2178d816ca8 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -132,15 +132,15 @@ public class TetheringConfiguration {
 
     public static final String TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION =
             "tether_force_random_prefix_base_selection";
+
+    public static final String TETHER_ENABLE_SYNC_SM = "tether_enable_sync_sm";
+
     /**
      * Default value that used to periodic polls tether offload stats from tethering offload HAL
      * to make the data warnings work.
      */
     public static final int DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS = 5000;
 
-    /** A flag for using synchronous or asynchronous state machine. */
-    public static final boolean USE_SYNC_SM = false;
-
     public final String[] tetherableUsbRegexs;
     public final String[] tetherableWifiRegexs;
     public final String[] tetherableWigigRegexs;
@@ -174,6 +174,7 @@ public class TetheringConfiguration {
 
     private final boolean mEnableWearTethering;
     private final boolean mRandomPrefixBase;
+    private final boolean mEnableSyncSm;
 
     private final int mUsbTetheringFunction;
     protected final ContentResolver mContentResolver;
@@ -292,6 +293,7 @@ public class TetheringConfiguration {
         mEnableWearTethering = shouldEnableWearTethering(ctx);
 
         mRandomPrefixBase = mDeps.isFeatureEnabled(ctx, TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION);
+        mEnableSyncSm = mDeps.isFeatureEnabled(ctx, TETHER_ENABLE_SYNC_SM);
 
         configLog.log(toString());
     }
@@ -385,6 +387,10 @@ public class TetheringConfiguration {
         return mRandomPrefixBase;
     }
 
+    public boolean isSyncSM() {
+        return mEnableSyncSm;
+    }
+
     /** Does the dumping.*/
     public void dump(PrintWriter pw) {
         pw.print("activeDataSubId: ");
@@ -438,6 +444,9 @@ public class TetheringConfiguration {
 
         pw.print("mRandomPrefixBase: ");
         pw.println(mRandomPrefixBase);
+
+        pw.print("mEnableSyncSm: ");
+        pw.println(mEnableSyncSm);
     }
 
     /** Returns the string representation of this object.*/
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
index aa322dc8ebb8fca80086c98318f55236be1b1424..19c6e5a6a1c2ce1c0466737e006f47cf2cef8057 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
@@ -754,4 +754,26 @@ public class TetheringConfigurationTest {
                 new TetheringConfiguration(mMockContext, mLog, INVALID_SUBSCRIPTION_ID, mDeps);
         assertEquals(p2pLeasesSubnetPrefixLength, p2pCfg.getP2pLeasesSubnetPrefixLength());
     }
+
+    private void setTetherEnableSyncSMFlagEnabled(Boolean enabled) {
+        mDeps.setFeatureEnabled(TetheringConfiguration.TETHER_ENABLE_SYNC_SM, enabled);
+    }
+
+    private void assertEnableSyncSMIs(boolean value) {
+        assertEquals(value, new TetheringConfiguration(
+                mMockContext, mLog, INVALID_SUBSCRIPTION_ID, mDeps).isSyncSM());
+    }
+
+    @Test
+    public void testEnableSyncSMFlag() throws Exception {
+        // Test default disabled
+        setTetherEnableSyncSMFlagEnabled(null);
+        assertEnableSyncSMIs(false);
+
+        setTetherEnableSyncSMFlagEnabled(true);
+        assertEnableSyncSMIs(true);
+
+        setTetherEnableSyncSMFlagEnabled(false);
+        assertEnableSyncSMIs(false);
+    }
 }