diff --git a/api/module-app-current.txt b/api/module-app-current.txt
index d802177..4307e67 100644
--- a/api/module-app-current.txt
+++ b/api/module-app-current.txt
@@ -1 +1,9 @@
 // Signature format: 2.0
+package android.app {
+
+  public final class NotificationChannel implements android.os.Parcelable {
+    method public void setBlockableSystem(boolean);
+  }
+
+}
+
diff --git a/core/java/android/app/NotificationChannel.java b/core/java/android/app/NotificationChannel.java
index bdc7b99..6a43465 100644
--- a/core/java/android/app/NotificationChannel.java
+++ b/core/java/android/app/NotificationChannel.java
@@ -15,6 +15,8 @@
  */
 package android.app;
 
+import static android.annotation.SystemApi.Client.MODULE_APPS;
+
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
@@ -350,9 +352,13 @@
     }
 
     /**
+     * Allows users to block notifications sent through this channel, if this channel belongs to
+     * a package that is signed with the system signature. If the channel does not belong to a
+     * package that is signed with the system signature, this method does nothing.
+     * @param blockableSystem if {@code true}, allows users to block notifications on this channel.
      * @hide
      */
-    @UnsupportedAppUsage
+    @SystemApi(client = MODULE_APPS)
     @TestApi
     public void setBlockableSystem(boolean blockableSystem) {
         mBlockableSystem = blockableSystem;