diff --git a/service-t/src/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java b/service-t/src/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java
index 13f6dac..805b5de 100644
--- a/service-t/src/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java
+++ b/service-t/src/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java
@@ -74,7 +74,7 @@
     @NonNull
     private final List<MdnsResponse> servicesToResolve;
     @NonNull
-    private final MdnsResponseDecoder.Clock clock;
+    private final MdnsUtils.Clock clock;
     private final boolean onlyUseIpv6OnIpv6OnlyNetworks;
 
     EnqueueMdnsQueryCallable(
@@ -88,7 +88,7 @@
             boolean onlyUseIpv6OnIpv6OnlyNetworks,
             boolean sendDiscoveryQueries,
             @NonNull Collection<MdnsResponse> servicesToResolve,
-            @NonNull MdnsResponseDecoder.Clock clock) {
+            @NonNull MdnsUtils.Clock clock) {
         weakRequestSender = new WeakReference<>(requestSender);
         this.packetWriter = packetWriter;
         serviceTypeLabels = TextUtils.split(serviceType, "\\.");
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java b/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
index eff1880..a0a538e 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
@@ -19,7 +19,6 @@
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.net.Network;
-import android.os.SystemClock;
 import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.Pair;
@@ -40,10 +39,10 @@
     private final boolean allowMultipleSrvRecordsPerHost =
             MdnsConfigs.allowMultipleSrvRecordsPerHost();
     @Nullable private final String[] serviceType;
-    private final Clock clock;
+    private final MdnsUtils.Clock clock;
 
     /** Constructs a new decoder that will extract responses for the given service type. */
-    public MdnsResponseDecoder(@NonNull Clock clock, @Nullable String[] serviceType) {
+    public MdnsResponseDecoder(@NonNull MdnsUtils.Clock clock, @Nullable String[] serviceType) {
         this.clock = clock;
         this.serviceType = serviceType;
     }
@@ -330,10 +329,4 @@
         }
         return result == null ? List.of() : result;
     }
-
-    public static class Clock {
-        public long elapsedRealtime() {
-            return SystemClock.elapsedRealtime();
-        }
-    }
 }
\ No newline at end of file
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
index b15defd..a103302 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
@@ -17,6 +17,7 @@
 package com.android.server.connectivity.mdns;
 
 import static com.android.server.connectivity.mdns.MdnsServiceCache.findMatchedResponse;
+import static com.android.server.connectivity.mdns.util.MdnsUtils.Clock;
 import static com.android.server.connectivity.mdns.util.MdnsUtils.ensureRunningOnHandlerThread;
 
 import android.annotation.NonNull;
@@ -73,7 +74,7 @@
             new ArrayMap<>();
     private final boolean removeServiceAfterTtlExpires =
             MdnsConfigs.removeServiceAfterTtlExpires();
-    private final MdnsResponseDecoder.Clock clock;
+    private final Clock clock;
 
     @Nullable private MdnsSearchOptions searchOptions;
 
@@ -193,8 +194,8 @@
             @NonNull SharedLog sharedLog,
             @NonNull Looper looper,
             @NonNull MdnsServiceCache serviceCache) {
-        this(serviceType, socketClient, executor, new MdnsResponseDecoder.Clock(), socketKey,
-                sharedLog, looper, new Dependencies(), serviceCache);
+        this(serviceType, socketClient, executor, new Clock(), socketKey, sharedLog, looper,
+                new Dependencies(), serviceCache);
     }
 
     @VisibleForTesting
@@ -202,7 +203,7 @@
             @NonNull String serviceType,
             @NonNull MdnsSocketClientBase socketClient,
             @NonNull ScheduledExecutorService executor,
-            @NonNull MdnsResponseDecoder.Clock clock,
+            @NonNull Clock clock,
             @NonNull SocketKey socketKey,
             @NonNull SharedLog sharedLog,
             @NonNull Looper looper,
diff --git a/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java b/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java
index 3180a6f..df3bde8 100644
--- a/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java
+++ b/service-t/src/com/android/server/connectivity/mdns/util/MdnsUtils.java
@@ -20,6 +20,7 @@
 import android.annotation.Nullable;
 import android.net.Network;
 import android.os.Handler;
+import android.os.SystemClock;
 import android.util.ArraySet;
 
 import com.android.server.connectivity.mdns.MdnsConstants;
@@ -173,4 +174,14 @@
         return mdnsRecord.getTtl() > 0
                 && mdnsRecord.getRemainingTTL(now) <= mdnsRecord.getTtl() / 2;
     }
+
+    /** A wrapper class of {@link SystemClock} to be mocked in unit tests. */
+    public static class Clock {
+        /**
+         * @see SystemClock#elapsedRealtime
+         */
+        public long elapsedRealtime() {
+            return SystemClock.elapsedRealtime();
+        }
+    }
 }
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
index 05eca84..d71bea4 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
@@ -18,7 +18,7 @@
 
 import static android.net.InetAddresses.parseNumericAddress;
 
-import static com.android.server.connectivity.mdns.MdnsResponseDecoder.Clock;
+import static com.android.server.connectivity.mdns.util.MdnsUtils.Clock;
 import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 
 import static org.junit.Assert.assertArrayEquals;
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
index 11c9653..8b36c33 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
@@ -53,6 +53,7 @@
 import com.android.net.module.util.SharedLog;
 import com.android.server.connectivity.mdns.MdnsServiceInfo.TextEntry;
 import com.android.server.connectivity.mdns.MdnsServiceTypeClient.QueryTaskConfig;
+import com.android.server.connectivity.mdns.util.MdnsUtils;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
 import com.android.testutils.HandlerUtils;
@@ -113,7 +114,7 @@
     @Mock
     private Network mockNetwork;
     @Mock
-    private MdnsResponseDecoder.Clock mockDecoderClock;
+    private MdnsUtils.Clock mockDecoderClock;
     @Mock
     private SharedLog mockSharedLog;
     @Mock