diff --git a/services/mediatranscoding/tests/MediaTranscodingServiceTestHelper.h b/services/mediatranscoding/tests/MediaTranscodingServiceTestHelper.h
index 66cced5..5256a3f 100644
--- a/services/mediatranscoding/tests/MediaTranscodingServiceTestHelper.h
+++ b/services/mediatranscoding/tests/MediaTranscodingServiceTestHelper.h
@@ -51,6 +51,7 @@
 using aidl::android::media::TranscodingRequestParcel;
 using aidl::android::media::TranscodingSessionParcel;
 using aidl::android::media::TranscodingSessionPriority;
+using aidl::android::media::TranscodingTestConfig;
 using aidl::android::media::TranscodingVideoTrackFormat;
 
 constexpr int32_t kClientUseCallingPid = IMediaTranscodingService::USE_CALLING_PID;
@@ -359,7 +360,8 @@
     template <bool expectation = success>
     bool submit(int32_t sessionId, const char* sourceFilePath, const char* destinationFilePath,
                 TranscodingSessionPriority priority = TranscodingSessionPriority::kNormal,
-                int bitrateBps = -1, int overridePid = -1, int overrideUid = -1) {
+                int bitrateBps = -1, int overridePid = -1, int overrideUid = -1,
+                int sessionDurationMs = -1) {
         constexpr bool shouldSucceed = (expectation == success);
         bool result;
         TranscodingRequestParcel request;
@@ -375,6 +377,11 @@
             request.requestedVideoTrackFormat.emplace(TranscodingVideoTrackFormat());
             request.requestedVideoTrackFormat->bitrateBps = bitrateBps;
         }
+        if (sessionDurationMs > 0) {
+            request.isForTesting = true;
+            request.testConfig.emplace(TranscodingTestConfig());
+            request.testConfig->processingTotalTimeMs = sessionDurationMs;
+        }
         Status status = mClient->submitRequest(request, &session, &result);
 
         EXPECT_TRUE(status.isOk());
diff --git a/services/mediatranscoding/tests/mediatranscodingservice_simulated_tests.cpp b/services/mediatranscoding/tests/mediatranscodingservice_simulated_tests.cpp
index 601bb1b..b8a6f76 100644
--- a/services/mediatranscoding/tests/mediatranscodingservice_simulated_tests.cpp
+++ b/services/mediatranscoding/tests/mediatranscodingservice_simulated_tests.cpp
@@ -53,6 +53,7 @@
 
 constexpr int64_t kPaddingUs = 1000000;
 constexpr int64_t kSessionWithPaddingUs = SimulatedTranscoder::kSessionDurationUs + kPaddingUs;
+constexpr int64_t kWatchdogTimeoutUs = 3000000;
 
 constexpr const char* kClientOpPackageName = "TestClientPackage";
 
@@ -385,5 +386,33 @@
 
     ALOGD("TestTranscodingThermalPolicy finished.");
 }
+
+TEST_F(MediaTranscodingServiceSimulatedTest, TestTranscodingWatchdog) {
+    ALOGD("TestTranscodingWatchdog starting...");
+
+    registerMultipleClients();
+
+    // SimulatedTranscoder itself does not send heartbeat. Its sessions last 1sec
+    // by default, so timeout will not happen normally.
+    // Here we run a session of 4000ms with TranscodingTestConfig. This will trigger
+    // a watchdog timeout on server side. We use it to check that error code is correct.
+    EXPECT_TRUE(mClient1->submit(
+            0, "test_source_file_0", "test_destination_file_0", TranscodingSessionPriority::kNormal,
+            -1 /*bitrateBps*/, -1 /*overridePid*/, -1 /*overrideUid*/, 4000 /*sessionDurationMs*/));
+    EXPECT_EQ(mClient1->pop(100000), EventTracker::Start(CLIENT(1), 0));
+    EXPECT_EQ(mClient1->pop(kWatchdogTimeoutUs - 100000), EventTracker::NoEvent);
+    EXPECT_EQ(mClient1->pop(200000), EventTracker::Failed(CLIENT(1), 0));
+    EXPECT_EQ(mClient1->getLastError(), TranscodingErrorCode::kWatchdogTimeout);
+
+    // After the timeout, submit another request and check it's finished.
+    EXPECT_TRUE(mClient1->submit(1, "test_source_file_1", "test_destination_file_1"));
+    EXPECT_EQ(mClient1->pop(kPaddingUs), EventTracker::Start(CLIENT(1), 1));
+    EXPECT_EQ(mClient1->pop(kSessionWithPaddingUs), EventTracker::Finished(CLIENT(1), 1));
+
+    unregisterMultipleClients();
+
+    ALOGD("TestTranscodingWatchdog finished.");
+}
+
 }  // namespace media
 }  // namespace android