diff --git a/framework/src/android/net/BpfNetMapsUtils.java b/framework/src/android/net/BpfNetMapsUtils.java
index 9cbf147..4e01fee 100644
--- a/framework/src/android/net/BpfNetMapsUtils.java
+++ b/framework/src/android/net/BpfNetMapsUtils.java
@@ -53,12 +53,15 @@
 import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
 import static android.system.OsConstants.EINVAL;
 
+import android.os.Build;
 import android.os.Process;
 import android.os.ServiceSpecificException;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.util.Pair;
 
+import androidx.annotation.RequiresApi;
+
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.Struct;
@@ -76,6 +79,8 @@
 // Note that this class should be put into bootclasspath instead of static libraries.
 // Because modules could have different copies of this class if this is statically linked,
 // which would be problematic if the definitions in these modules are not synchronized.
+// Note that NetworkStack can not use this before U due to b/326143935
+@RequiresApi(Build.VERSION_CODES.TIRAMISU)
 public class BpfNetMapsUtils {
     // Bitmaps for calculating whether a given uid is blocked by firewall chains.
     private static final long sMaskDropIfSet;
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index 01bd71e..04d8ea4 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -579,6 +579,7 @@
         return BpfNetMapsUtils.getUidRule(sUidOwnerMap, childChain, uid);
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private Set<Integer> getUidsMatchEnabled(final int childChain) throws ErrnoException {
         final long match = getMatchByFirewallChain(childChain);
         Set<Integer> uids = new ArraySet<>();
@@ -607,6 +608,7 @@
      * @param childChain target chain
      * @return Set of uids
      */
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     public Set<Integer> getUidsWithAllowRuleOnAllowListChain(final int childChain)
             throws ErrnoException {
         if (!isFirewallAllowList(childChain)) {
@@ -628,6 +630,7 @@
      * @param childChain target chain
      * @return Set of uids
      */
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     public Set<Integer> getUidsWithDenyRuleOnDenyListChain(final int childChain)
             throws ErrnoException {
         if (isFirewallAllowList(childChain)) {
@@ -922,6 +925,7 @@
         return sj.toString();
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private void dumpOwnerMatchConfig(final IndentingPrintWriter pw) {
         try {
             final long match = sConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY).val;
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 0ea3366..a34c0a9 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -13555,6 +13555,7 @@
         return rule;
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private void closeSocketsForFirewallChainLocked(final int chain)
             throws ErrnoException, SocketException, InterruptedIOException {
         if (BpfNetMapsUtils.isFirewallAllowList(chain)) {