diff --git a/service-t/src/com/android/server/net/NetworkStatsService.java b/service-t/src/com/android/server/net/NetworkStatsService.java
index 39a705f..0da7b6f 100644
--- a/service-t/src/com/android/server/net/NetworkStatsService.java
+++ b/service-t/src/com/android/server/net/NetworkStatsService.java
@@ -164,7 +164,7 @@
 import com.android.net.module.util.PermissionUtils;
 import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.Struct;
-import com.android.net.module.util.Struct.U32;
+import com.android.net.module.util.Struct.S32;
 import com.android.net.module.util.Struct.U8;
 import com.android.net.module.util.bpf.CookieTagMapKey;
 import com.android.net.module.util.bpf.CookieTagMapValue;
@@ -408,7 +408,7 @@
      * mActiveUidCounterSet to avoid accessing kernel too frequently.
      */
     private SparseIntArray mActiveUidCounterSet = new SparseIntArray();
-    private final IBpfMap<U32, U8> mUidCounterSetMap;
+    private final IBpfMap<S32, U8> mUidCounterSetMap;
     private final IBpfMap<CookieTagMapKey, CookieTagMapValue> mCookieTagMap;
     private final IBpfMap<StatsMapKey, StatsMapValue> mStatsMapA;
     private final IBpfMap<StatsMapKey, StatsMapValue> mStatsMapB;
@@ -741,10 +741,10 @@
         }
 
         /** Get counter sets map for each UID. */
-        public IBpfMap<U32, U8> getUidCounterSetMap() {
+        public IBpfMap<S32, U8> getUidCounterSetMap() {
             try {
-                return new BpfMap<U32, U8>(UID_COUNTERSET_MAP_PATH, BpfMap.BPF_F_RDWR,
-                        U32.class, U8.class);
+                return new BpfMap<S32, U8>(UID_COUNTERSET_MAP_PATH, BpfMap.BPF_F_RDWR,
+                        S32.class, U8.class);
             } catch (ErrnoException e) {
                 Log.wtf(TAG, "Cannot open uid counter set map: " + e);
                 return null;
@@ -1747,7 +1747,7 @@
 
         if (set == SET_DEFAULT) {
             try {
-                mUidCounterSetMap.deleteEntry(new U32(uid));
+                mUidCounterSetMap.deleteEntry(new S32(uid));
             } catch (ErrnoException e) {
                 Log.w(TAG, "UidCounterSetMap.deleteEntry(" + uid + ") failed with errno: " + e);
             }
@@ -1755,7 +1755,7 @@
         }
 
         try {
-            mUidCounterSetMap.updateEntry(new U32(uid), new U8((short) set));
+            mUidCounterSetMap.updateEntry(new S32(uid), new U8((short) set));
         } catch (ErrnoException e) {
             Log.w(TAG, "UidCounterSetMap.updateEntry(" + uid + ", " + set
                     + ") failed with errno: " + e);
@@ -2472,7 +2472,7 @@
         deleteStatsMapTagData(mStatsMapB, uid);
 
         try {
-            mUidCounterSetMap.deleteEntry(new U32(uid));
+            mUidCounterSetMap.deleteEntry(new S32(uid));
         } catch (ErrnoException e) {
             logErrorIfNotErrNoent(e, "Failed to delete tag data from uid counter set map");
         }
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
index fdbccba..6448819 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -139,7 +139,7 @@
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.LocationPermissionChecker;
 import com.android.net.module.util.Struct;
-import com.android.net.module.util.Struct.U32;
+import com.android.net.module.util.Struct.S32;
 import com.android.net.module.util.Struct.U8;
 import com.android.net.module.util.bpf.CookieTagMapKey;
 import com.android.net.module.util.bpf.CookieTagMapValue;
@@ -249,7 +249,7 @@
     private HandlerThread mHandlerThread;
     @Mock
     private LocationPermissionChecker mLocationPermissionChecker;
-    private TestBpfMap<U32, U8> mUidCounterSetMap = spy(new TestBpfMap<>(U32.class, U8.class));
+    private TestBpfMap<S32, U8> mUidCounterSetMap = spy(new TestBpfMap<>(S32.class, U8.class));
     @Mock
     private BpfNetMaps mBpfNetMaps;
     @Mock
@@ -478,7 +478,7 @@
             }
 
             @Override
-            public IBpfMap<U32, U8> getUidCounterSetMap() {
+            public IBpfMap<S32, U8> getUidCounterSetMap() {
                 return mUidCounterSetMap;
             }
 
@@ -646,7 +646,7 @@
         mService.incrementOperationCount(UID_RED, 0xFAAD, 4);
         mService.noteUidForeground(UID_RED, true);
         verify(mUidCounterSetMap).updateEntry(
-                eq(new U32(UID_RED)), eq(new U8((short) SET_FOREGROUND)));
+                eq(new S32(UID_RED)), eq(new U8((short) SET_FOREGROUND)));
         mService.incrementOperationCount(UID_RED, 0xFAAD, 6);
 
         forcePollAndWaitForIdle();
@@ -1311,7 +1311,7 @@
                 .insertEntry(TEST_IFACE, UID_RED, SET_FOREGROUND, 0xFAAD, 1L, 1L, 1L, 1L, 0L));
         mService.noteUidForeground(UID_RED, true);
         verify(mUidCounterSetMap).updateEntry(
-                eq(new U32(UID_RED)), eq(new U8((short) SET_FOREGROUND)));
+                eq(new S32(UID_RED)), eq(new U8((short) SET_FOREGROUND)));
         mService.incrementOperationCount(UID_RED, 0xFAAD, 1);
 
         forcePollAndWaitForIdle();
@@ -1927,7 +1927,7 @@
         mService.incrementOperationCount(UID_RED, 0xFAAD, 4);
         mService.noteUidForeground(UID_RED, true);
         verify(mUidCounterSetMap).updateEntry(
-                eq(new U32(UID_RED)), eq(new U8((short) SET_FOREGROUND)));
+                eq(new S32(UID_RED)), eq(new U8((short) SET_FOREGROUND)));
         mService.incrementOperationCount(UID_RED, 0xFAAD, 6);
 
         forcePollAndWaitForIdle();
@@ -2424,13 +2424,13 @@
 
         mAppUidStatsMap.insertEntry(new UidStatsMapKey(uid), new StatsMapValue(10, 10000, 6, 6000));
 
-        mUidCounterSetMap.insertEntry(new U32(uid), new U8((short) 1));
+        mUidCounterSetMap.insertEntry(new S32(uid), new U8((short) 1));
 
         assertTrue(cookieTagMapContainsUid(uid));
         assertTrue(statsMapContainsUid(mStatsMapA, uid));
         assertTrue(statsMapContainsUid(mStatsMapB, uid));
         assertTrue(mAppUidStatsMap.containsKey(new UidStatsMapKey(uid)));
-        assertTrue(mUidCounterSetMap.containsKey(new U32(uid)));
+        assertTrue(mUidCounterSetMap.containsKey(new S32(uid)));
     }
 
     @Test
@@ -2447,14 +2447,14 @@
         assertFalse(statsMapContainsUid(mStatsMapA, UID_BLUE));
         assertFalse(statsMapContainsUid(mStatsMapB, UID_BLUE));
         assertFalse(mAppUidStatsMap.containsKey(new UidStatsMapKey(UID_BLUE)));
-        assertFalse(mUidCounterSetMap.containsKey(new U32(UID_BLUE)));
+        assertFalse(mUidCounterSetMap.containsKey(new S32(UID_BLUE)));
 
         // assert that UID_RED related tag data is still in the maps.
         assertTrue(cookieTagMapContainsUid(UID_RED));
         assertTrue(statsMapContainsUid(mStatsMapA, UID_RED));
         assertTrue(statsMapContainsUid(mStatsMapB, UID_RED));
         assertTrue(mAppUidStatsMap.containsKey(new UidStatsMapKey(UID_RED)));
-        assertTrue(mUidCounterSetMap.containsKey(new U32(UID_RED)));
+        assertTrue(mUidCounterSetMap.containsKey(new S32(UID_RED)));
     }
 
     private void assertDumpContains(final String dump, final String message) {