diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 16b42dcf9f..35b2d41a65 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -2,6 +2,10 @@
 
 ### dev-v2 (not yet released) ###
 
+* Add `ExoCastPlayer` to cast to custom receiver apps using ExoPlayer's custom
+  communication protocol
+  ([#5486](https://github.com/google/ExoPlayer/issues/5486)). Also update the
+  Cast demo app to work with `ExoCastPlayer`.
 * HLS:
   * Form an adaptive track group out of audio renditions with matching name.
 * `ExtractorMediaSource` renamed to `ProgressiveMediaSource`.
diff --git a/demos/cast/build.gradle b/demos/cast/build.gradle
index e056530d45..c898557cab 100644
--- a/demos/cast/build.gradle
+++ b/demos/cast/build.gradle
@@ -52,6 +52,11 @@ android {
     flavorDimensions "receiver"
 
     productFlavors {
+        exoCast {
+            dimension "receiver"
+            manifestPlaceholders =
+                    [castOptionsProvider: "com.google.android.exoplayer2.ext.cast.ExoCastOptionsProvider"]
+        }
         defaultCast {
             dimension "receiver"
             manifestPlaceholders =
diff --git a/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/MainActivity.java b/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/MainActivity.java
index 48934abd2c..7b525b04be 100644
--- a/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/MainActivity.java
+++ b/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/MainActivity.java
@@ -128,6 +128,15 @@ public class MainActivity extends AppCompatActivity
                 /* context= */ this,
                 castContext);
         break;
+      case ExoCastOptionsProvider.RECEIVER_ID:
+        playerManager =
+            new ExoCastPlayerManager(
+                /* queueChangesListener= */ this,
+                localPlayerView,
+                castControlView,
+                /* context= */ this,
+                castContext);
+        break;
       default:
         throw new IllegalStateException("Illegal receiver app id: " + applicationId);
     }