diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidationListener.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidationListener.java
index 971f455b1c..82ed65826a 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidationListener.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidationListener.java
@@ -39,6 +39,7 @@ public interface UploadValidationListener {
    * @param repository The repository
    * @param project The project
    * @param remoteHost Remote address/hostname of the user
+   * @param up the UploadPack instance being processed
    * @param wants The list of wanted objects. These may be RevObject or RevCommit if the processor
    *     parsed them. Implementors should not rely on the values being parsed.
    * @param haves The list of common objects. Empty on an initial clone request. These may be
@@ -47,12 +48,34 @@ public interface UploadValidationListener {
    * @throws ValidationException to block the upload and send a message back to the end-user over
    *     the client's protocol connection.
    */
-  void onPreUpload(
+  default void onPreUpload(
       Repository repository,
       Project project,
       String remoteHost,
       UploadPack up,
       Collection<? extends ObjectId> wants,
       Collection<? extends ObjectId> haves)
-      throws ValidationException;
+      throws ValidationException {}
+
+  /**
+   * Invoked before negotiation round is started.
+   *
+   * @param repository The repository
+   * @param project The project
+   * @param remoteHost Remote address/hostname of the user
+   * @param up the UploadPack instance being processed
+   * @param wants The list of wanted objects. These may be RevObject or RevCommit if the processor
+   *     parsed them. Implementors should not rely on the values being parsed.
+   * @param cntOffered number of objects the client has offered.
+   * @throws ValidationException to block the upload and send a message back to the end-user over
+   *     the client's protocol connection.
+   */
+  default void onBeginNegotiate(
+      Repository repository,
+      Project project,
+      String remoteHost,
+      UploadPack up,
+      Collection<? extends ObjectId> wants,
+      int cntOffered)
+      throws ValidationException {}
 }
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidators.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidators.java
index 52b76e8559..84d4586aaa 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidators.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/UploadValidators.java
@@ -65,7 +65,15 @@ public class UploadValidators implements PreUploadHook {
   @Override
   public void onBeginNegotiateRound(
       UploadPack up, Collection<? extends ObjectId> wants, int cntOffered)
-      throws ServiceMayNotContinueException {}
+      throws ServiceMayNotContinueException {
+    for (UploadValidationListener validator : uploadValidationListeners) {
+      try {
+        validator.onBeginNegotiate(repository, project, remoteHost, up, wants, cntOffered);
+      } catch (ValidationException e) {
+        throw new UploadValidationException(e.getMessage());
+      }
+    }
+  }
 
   @Override
   public void onEndNegotiateRound(