diff --git a/library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java b/library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java
index 044dbf13a9..7922e93447 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java
@@ -96,6 +96,8 @@ public final class MimeTypes {
   public static final String TEXT_VTT = BASE_TYPE_TEXT + "/vtt";
   public static final String TEXT_SSA = BASE_TYPE_TEXT + "/x-ssa";
 
+  public static final String TEXT_EXOPLAYER_CUES = BASE_TYPE_TEXT + "/x-exoplayer-cues";
+
   // application/ MIME types
 
   public static final String APPLICATION_MP4 = BASE_TYPE_APPLICATION + "/mp4";
diff --git a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractor.java b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractor.java
index d7ee336f4f..eee12e4810 100644
--- a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractor.java
+++ b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractor.java
@@ -34,6 +34,7 @@ import com.google.android.exoplayer2.text.SubtitleDecoder;
 import com.google.android.exoplayer2.text.SubtitleDecoderException;
 import com.google.android.exoplayer2.text.SubtitleInputBuffer;
 import com.google.android.exoplayer2.text.SubtitleOutputBuffer;
+import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.common.primitives.Ints;
 import java.io.IOException;
@@ -94,7 +95,12 @@ public class SubtitleExtractor implements Extractor {
     this.subtitleDecoder = subtitleDecoder;
     cueEncoder = new CueEncoder();
     subtitleData = new ParsableByteArray();
-    this.format = format;
+    this.format =
+        format
+            .buildUpon()
+            .setSampleMimeType(MimeTypes.TEXT_EXOPLAYER_CUES)
+            .setCodecs(format.sampleMimeType)
+            .build();
     state = STATE_CREATED;
   }
 
diff --git a/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractorTest.java b/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractorTest.java
index 9d516d2e2a..9366d3db43 100644
--- a/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractorTest.java
+++ b/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/subtitle/SubtitleExtractorTest.java
@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.testutil.FakeTrackOutput;
 import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.text.CueDecoder;
 import com.google.android.exoplayer2.text.webvtt.WebvttDecoder;
+import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import java.util.List;
 import org.junit.Test;
@@ -56,12 +57,16 @@ public class SubtitleExtractorTest {
             .setSimulatePartialReads(true)
             .build();
     SubtitleExtractor extractor =
-        new SubtitleExtractor(new WebvttDecoder(), new Format.Builder().build());
+        new SubtitleExtractor(
+            new WebvttDecoder(),
+            new Format.Builder().setSampleMimeType(MimeTypes.TEXT_VTT).build());
     extractor.init(output);
 
     while (extractor.read(input, null) != Extractor.RESULT_END_OF_INPUT) {}
 
     FakeTrackOutput trackOutput = output.trackOutputs.get(0);
+    assertThat(trackOutput.lastFormat.sampleMimeType).isEqualTo(MimeTypes.TEXT_EXOPLAYER_CUES);
+    assertThat(trackOutput.lastFormat.codecs).isEqualTo(MimeTypes.TEXT_VTT);
     assertThat(trackOutput.getSampleCount()).isEqualTo(6);
     // Check sample timestamps.
     assertThat(trackOutput.getSampleTimeUs(0)).isEqualTo(0L);