diff --git a/Cronet/tests/cts/src/android/net/http/cts/UrlRequestTest.java b/Cronet/tests/cts/src/android/net/http/cts/UrlRequestTest.java
index a364e29..2ec035b 100644
--- a/Cronet/tests/cts/src/android/net/http/cts/UrlRequestTest.java
+++ b/Cronet/tests/cts/src/android/net/http/cts/UrlRequestTest.java
@@ -44,6 +44,8 @@
 import android.net.http.cts.util.TestUrlRequestCallback.ResponseStep;
 import android.net.http.cts.util.UploadDataProviders;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 
@@ -310,7 +312,7 @@
         assertThat(mCallback.mResponseAsString).isEqualTo(body);
     }
 
-    private static class StubUrlRequestCallback extends UrlRequest.Callback {
+    private static class StubUrlRequestCallback implements UrlRequest.Callback {
 
         @Override
         public void onRedirectReceived(
@@ -338,6 +340,11 @@
         public void onFailed(UrlRequest request, UrlResponseInfo info, HttpException error) {
             throw new UnsupportedOperationException(error);
         }
+
+        @Override
+        public void onCanceled(@NonNull UrlRequest request, @Nullable UrlResponseInfo info) {
+            throw new UnsupportedOperationException();
+        }
     }
 
     private static class InMemoryUploadDataProvider extends UploadDataProvider {
diff --git a/Cronet/tests/cts/src/android/net/http/cts/util/TestUrlRequestCallback.java b/Cronet/tests/cts/src/android/net/http/cts/util/TestUrlRequestCallback.java
index efbcff6..28443b7 100644
--- a/Cronet/tests/cts/src/android/net/http/cts/util/TestUrlRequestCallback.java
+++ b/Cronet/tests/cts/src/android/net/http/cts/util/TestUrlRequestCallback.java
@@ -50,7 +50,7 @@
  * method to block thread until the request completes on another thread.
  * Allows us to cancel, block request or throw an exception from an arbitrary step.
  */
-public class TestUrlRequestCallback extends UrlRequest.Callback {
+public class TestUrlRequestCallback implements UrlRequest.Callback {
     private static final int TIMEOUT_MS = 12_000;
     public ArrayList<UrlResponseInfo> mRedirectResponseInfoList = new ArrayList<>();
     public ArrayList<String> mRedirectUrlList = new ArrayList<>();
diff --git a/Tethering/common/TetheringLib/cronet_enabled/api/current.txt b/Tethering/common/TetheringLib/cronet_enabled/api/current.txt
index cf441ce..66a0295 100644
--- a/Tethering/common/TetheringLib/cronet_enabled/api/current.txt
+++ b/Tethering/common/TetheringLib/cronet_enabled/api/current.txt
@@ -241,14 +241,13 @@
     method @NonNull public abstract android.net.http.UrlRequest.Builder setUploadDataProvider(@NonNull android.net.http.UploadDataProvider, @NonNull java.util.concurrent.Executor);
   }
 
-  public abstract static class UrlRequest.Callback {
-    ctor public UrlRequest.Callback();
+  public static interface UrlRequest.Callback {
     method public void onCanceled(@NonNull android.net.http.UrlRequest, @Nullable android.net.http.UrlResponseInfo);
-    method public abstract void onFailed(@NonNull android.net.http.UrlRequest, @Nullable android.net.http.UrlResponseInfo, @NonNull android.net.http.HttpException);
-    method public abstract void onReadCompleted(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo, @NonNull java.nio.ByteBuffer) throws java.lang.Exception;
-    method public abstract void onRedirectReceived(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo, @NonNull String) throws java.lang.Exception;
-    method public abstract void onResponseStarted(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo) throws java.lang.Exception;
-    method public abstract void onSucceeded(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo);
+    method public void onFailed(@NonNull android.net.http.UrlRequest, @Nullable android.net.http.UrlResponseInfo, @NonNull android.net.http.HttpException);
+    method public void onReadCompleted(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo, @NonNull java.nio.ByteBuffer) throws java.lang.Exception;
+    method public void onRedirectReceived(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo, @NonNull String) throws java.lang.Exception;
+    method public void onResponseStarted(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo) throws java.lang.Exception;
+    method public void onSucceeded(@NonNull android.net.http.UrlRequest, @NonNull android.net.http.UrlResponseInfo);
   }
 
   public static class UrlRequest.Status {