diff --git a/packager/media/formats/webvtt/webvtt_output_handler_unittest.cc b/packager/media/formats/webvtt/webvtt_output_handler_unittest.cc
index 5741d3748e..f381249bbb 100644
--- a/packager/media/formats/webvtt/webvtt_output_handler_unittest.cc
+++ b/packager/media/formats/webvtt/webvtt_output_handler_unittest.cc
@@ -11,12 +11,15 @@
 #include "packager/media/base/media_handler_test_base.h"
 #include "packager/media/base/text_stream_info.h"
 #include "packager/media/event/combined_muxer_listener.h"
+#include "packager/media/event/mock_muxer_listener.h"
 #include "packager/media/formats/webvtt/webvtt_output_handler.h"
 #include "packager/status_test_util.h"
 
 namespace shaka {
 namespace media {
 namespace {
+using testing::_;
+
 const size_t kInputCount = 1;
 const size_t kOutputCount = 0;
 const size_t kInputIndex = 0;
@@ -28,6 +31,9 @@ const char* kNoId = "";
 const char* kSegmentedFileTemplate = "memory://output/template-$Number$.vtt";
 const char* kSegmentedFileOutput1 = "memory://output/template-1.vtt";
 const char* kSegmentedFileOutput2 = "memory://output/template-2.vtt";
+
+const uint64_t kSegmentDuration = 10000;
+const float kMillisecondsPerSecond = 1000.0f;
 }  // namespace
 
 class WebVttSegmentedOutputTest : public MediaHandlerTestBase {
@@ -35,7 +41,11 @@ class WebVttSegmentedOutputTest : public MediaHandlerTestBase {
   void SetUp() {
     MuxerOptions muxer_options;
     muxer_options.segment_template = kSegmentedFileTemplate;
-    std::unique_ptr<MuxerListener> muxer_listener(new CombinedMuxerListener());
+
+    // Create a mock muxer listener but save a reference to the mock so that we
+    // can use it in the test.
+    std::unique_ptr<MockMuxerListener> muxer_listener(new MockMuxerListener);
+    muxer_listener_ = muxer_listener.get();
 
     out_ = std::make_shared<WebVttSegmentedOutputHandler>(
         muxer_options, std::move(muxer_listener));
@@ -43,20 +53,27 @@ class WebVttSegmentedOutputTest : public MediaHandlerTestBase {
     ASSERT_OK(SetUpAndInitializeGraph(out_, kInputCount, kOutputCount));
   }
 
+  MockMuxerListener* muxer_listener_ = nullptr;
   std::shared_ptr<WebVttSegmentedOutputHandler> out_;
 };
 
 TEST_F(WebVttSegmentedOutputTest, WithNoSegmentAndWithNoSamples) {
-  // Expected output - No files should be created as there were no
-  //                   samples.
+  EXPECT_CALL(*muxer_listener_, OnNewSegment(_, _, _, _)).Times(0);
+
+  {
+    // No segments should  have be created as there were no samples.
+
+    testing::InSequence s;
+    EXPECT_CALL(*muxer_listener_, OnMediaStart(_, _, _, _));
+
+    const float kMediaDuration = 0 * kSegmentDuration / kMillisecondsPerSecond;
+    EXPECT_CALL(*muxer_listener_,
+                OnMediaEndMock(_, _, _, _, _, _, _, _, kMediaDuration));
+  }
 
   ASSERT_OK(Input(kInputIndex)
                 ->Dispatch(StreamData::FromStreamInfo(kStreamIndex,
                                                       GetTextStreamInfo())));
-  ASSERT_OK(
-      Input(kInputIndex)
-          ->Dispatch(StreamData::FromSegmentInfo(
-              kStreamIndex, GetSegmentInfo(kStreamIndex, 10000, !kEncrypted))));
   ASSERT_OK(Input(kInputIndex)->FlushAllDownstreams());
 }
 
@@ -68,6 +85,20 @@ TEST_F(WebVttSegmentedOutputTest, WithOneSegmentAndWithOneSample) {
       "payload\n"
       "\n";
 
+  const uint64_t kSegmentStart = 0;
+
+  {
+    testing::InSequence s;
+    EXPECT_CALL(*muxer_listener_, OnMediaStart(_, _, _, _));
+    EXPECT_CALL(*muxer_listener_,
+                OnNewSegment(kSegmentedFileOutput1, kSegmentStart,
+                             kSegmentDuration, _));
+
+    const float kMediaDuration = 1 * kSegmentDuration / kMillisecondsPerSecond;
+    EXPECT_CALL(*muxer_listener_,
+                OnMediaEndMock(_, _, _, _, _, _, _, _, kMediaDuration));
+  }
+
   ASSERT_OK(Input(kInputIndex)
                 ->Dispatch(StreamData::FromStreamInfo(kStreamIndex,
                                                       GetTextStreamInfo())));
@@ -75,9 +106,11 @@ TEST_F(WebVttSegmentedOutputTest, WithOneSegmentAndWithOneSample) {
       Input(kInputIndex)
           ->Dispatch(StreamData::FromTextSample(
               kStreamIndex, GetTextSample(kNoId, 5000, 6000, "payload"))));
-  ASSERT_OK(Input(kInputIndex)
-                ->Dispatch(StreamData::FromSegmentInfo(
-                    kStreamIndex, GetSegmentInfo(0, 10000, !kEncrypted))));
+  ASSERT_OK(
+      Input(kInputIndex)
+          ->Dispatch(StreamData::FromSegmentInfo(
+              kStreamIndex,
+              GetSegmentInfo(kSegmentStart, kSegmentDuration, !kEncrypted))));
   ASSERT_OK(Input(kInputIndex)->FlushAllDownstreams());
 
   ASSERT_FILE_STREQ(kSegmentedFileOutput1, kExpectedOutput);
@@ -98,6 +131,24 @@ TEST_F(WebVttSegmentedOutputTest, WithTwoSegmentAndWithOneSample) {
       "payload 2\n"
       "\n";
 
+  const uint64_t kSegment1Start = 0;
+  const uint64_t kSegment2Start = kSegmentDuration;
+
+  {
+    testing::InSequence s;
+    EXPECT_CALL(*muxer_listener_, OnMediaStart(_, _, _, _));
+    EXPECT_CALL(*muxer_listener_,
+                OnNewSegment(kSegmentedFileOutput1, kSegment1Start,
+                             kSegmentDuration, _));
+    EXPECT_CALL(*muxer_listener_,
+                OnNewSegment(kSegmentedFileOutput2, kSegment2Start,
+                             kSegmentDuration, _));
+
+    const float kMediaDuration = 2 * kSegmentDuration / kMillisecondsPerSecond;
+    EXPECT_CALL(*muxer_listener_,
+                OnMediaEndMock(_, _, _, _, _, _, _, _, kMediaDuration));
+  }
+
   ASSERT_OK(Input(kInputIndex)
                 ->Dispatch(StreamData::FromStreamInfo(0, GetTextStreamInfo())));
 
@@ -106,17 +157,21 @@ TEST_F(WebVttSegmentedOutputTest, WithTwoSegmentAndWithOneSample) {
       Input(kInputIndex)
           ->Dispatch(StreamData::FromTextSample(
               kStreamIndex, GetTextSample(kNoId, 5000, 6000, "payload 1"))));
-  ASSERT_OK(Input(kInputIndex)
-                ->Dispatch(StreamData::FromSegmentInfo(
-                    kStreamIndex, GetSegmentInfo(0, 10000, !kEncrypted))));
+  ASSERT_OK(
+      Input(kInputIndex)
+          ->Dispatch(StreamData::FromSegmentInfo(
+              kStreamIndex,
+              GetSegmentInfo(kSegment1Start, kSegmentDuration, !kEncrypted))));
   // Segment Two
   ASSERT_OK(
       Input(kInputIndex)
           ->Dispatch(StreamData::FromTextSample(
               kStreamIndex, GetTextSample(kNoId, 15000, 16000, "payload 2"))));
-  ASSERT_OK(Input(kInputIndex)
-                ->Dispatch(StreamData::FromSegmentInfo(
-                    kStreamIndex, GetSegmentInfo(10000, 10000, !kEncrypted))));
+  ASSERT_OK(
+      Input(kInputIndex)
+          ->Dispatch(StreamData::FromSegmentInfo(
+              kStreamIndex,
+              GetSegmentInfo(kSegment2Start, kSegmentDuration, !kEncrypted))));
   ASSERT_OK(Input(kInputIndex)->FlushAllDownstreams());
 
   ASSERT_FILE_STREQ(kSegmentedFileOutput1, kExpectedOutput1);
@@ -124,32 +179,57 @@ TEST_F(WebVttSegmentedOutputTest, WithTwoSegmentAndWithOneSample) {
 }
 
 TEST_F(WebVttSegmentedOutputTest, WithAnEmptySegment) {
-  const char* kExpectedOutput =
+  const char* kExpectedOutput1 =
+      "WEBVTT\n"
+      "\n";
+
+  const char* kExpectedOutput2 =
       "WEBVTT\n"
       "\n"
       "00:00:15.000 --> 00:00:16.000\n"
       "payload 2\n"
       "\n";
 
+  const uint64_t kSegment1Start = 0;
+  const uint64_t kSegment2Start = kSegmentDuration;
+
+  {
+    testing::InSequence s;
+    EXPECT_CALL(*muxer_listener_, OnMediaStart(_, _, _, _));
+    EXPECT_CALL(*muxer_listener_,
+                OnNewSegment(kSegmentedFileOutput1, kSegment1Start,
+                             kSegmentDuration, _));
+    EXPECT_CALL(*muxer_listener_,
+                OnNewSegment(kSegmentedFileOutput2, kSegment2Start,
+                             kSegmentDuration, _));
+
+    const float kMediaDuration = 2 * kSegmentDuration / kMillisecondsPerSecond;
+    EXPECT_CALL(*muxer_listener_,
+                OnMediaEndMock(_, _, _, _, _, _, _, _, kMediaDuration));
+  }
+
   ASSERT_OK(Input(kInputIndex)
                 ->Dispatch(StreamData::FromStreamInfo(0, GetTextStreamInfo())));
   // Segment One
-  ASSERT_OK(Input(kInputIndex)
-                ->Dispatch(StreamData::FromSegmentInfo(
-                    kStreamIndex, GetSegmentInfo(0, 10000, !kEncrypted))));
+  ASSERT_OK(
+      Input(kInputIndex)
+          ->Dispatch(StreamData::FromSegmentInfo(
+              kStreamIndex,
+              GetSegmentInfo(kSegment1Start, kSegmentDuration, !kEncrypted))));
   // Segment Two
   ASSERT_OK(
       Input(kInputIndex)
           ->Dispatch(StreamData::FromTextSample(
               kStreamIndex, GetTextSample(kNoId, 15000, 16000, "payload 2"))));
-  ASSERT_OK(Input(kInputIndex)
-                ->Dispatch(StreamData::FromSegmentInfo(
-                    kStreamIndex, GetSegmentInfo(10000, 10000, !kEncrypted))));
+  ASSERT_OK(
+      Input(kInputIndex)
+          ->Dispatch(StreamData::FromSegmentInfo(
+              kStreamIndex,
+              GetSegmentInfo(kSegment2Start, kSegmentDuration, !kEncrypted))));
   ASSERT_OK(Input(kInputIndex)->FlushAllDownstreams());
 
-  // The empty segment will not write to disk, but it will use segment's
-  // filename.
-  ASSERT_FILE_STREQ(kSegmentedFileOutput2, kExpectedOutput);
+  ASSERT_FILE_STREQ(kSegmentedFileOutput1, kExpectedOutput1);
+  ASSERT_FILE_STREQ(kSegmentedFileOutput2, kExpectedOutput2);
 }
 }  // namespace media
 }  // namespace shaka