diff --git a/java/com/google/gerrit/server/change/ConsistencyChecker.java b/java/com/google/gerrit/server/change/ConsistencyChecker.java
index a149935fcc..e10197fc04 100644
--- a/java/com/google/gerrit/server/change/ConsistencyChecker.java
+++ b/java/com/google/gerrit/server/change/ConsistencyChecker.java
@@ -52,6 +52,7 @@ import com.google.gerrit.server.patch.PatchSetInfoFactory;
 import com.google.gerrit.server.patch.PatchSetInfoNotAvailableException;
 import com.google.gerrit.server.update.BatchUpdate;
 import com.google.gerrit.server.update.BatchUpdateOp;
+import com.google.gerrit.server.update.BatchUpdateReviewDb;
 import com.google.gerrit.server.update.ChangeContext;
 import com.google.gerrit.server.update.RepoContext;
 import com.google.gerrit.server.update.RetryHelper;
@@ -667,7 +668,7 @@ public class ConsistencyChecker {
     public boolean updateChange(ChangeContext ctx)
         throws OrmException, PatchSetInfoNotAvailableException {
       // Delete dangling key references.
-      ReviewDb db = DeleteChangeOp.unwrap(ctx.getDb());
+      ReviewDb db = BatchUpdateReviewDb.unwrap(ctx.getDb());
       accountPatchReviewStore.get().clearReviewed(psId);
       db.changeMessages().delete(db.changeMessages().byChange(psId.getParentKey()));
       db.patchSetApprovals().delete(db.patchSetApprovals().byPatchSet(psId));
diff --git a/java/com/google/gerrit/server/change/DeleteChangeOp.java b/java/com/google/gerrit/server/change/DeleteChangeOp.java
index 8df6e59ed1..130d04076f 100644
--- a/java/com/google/gerrit/server/change/DeleteChangeOp.java
+++ b/java/com/google/gerrit/server/change/DeleteChangeOp.java
@@ -23,7 +23,6 @@ import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.server.ReviewDb;
-import com.google.gerrit.reviewdb.server.ReviewDbUtil;
 import com.google.gerrit.server.PatchSetUtil;
 import com.google.gerrit.server.StarredChangesUtil;
 import com.google.gerrit.server.project.NoSuchChangeException;
@@ -47,16 +46,6 @@ class DeleteChangeOp implements BatchUpdateOp {
     return cfg.getBoolean("change", "allowDrafts", true);
   }
 
-  static ReviewDb unwrap(ReviewDb db) {
-    // This is special. We want to delete exactly the rows that are present in
-    // the database, even when reading everything else from NoteDb, so we need
-    // to bypass the write-only wrapper.
-    if (db instanceof BatchUpdateReviewDb) {
-      db = ((BatchUpdateReviewDb) db).unsafeGetDelegate();
-    }
-    return ReviewDbUtil.unwrapDb(db);
-  }
-
   private final PatchSetUtil psUtil;
   private final StarredChangesUtil starredChangesUtil;
   private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
@@ -123,7 +112,11 @@ class DeleteChangeOp implements BatchUpdateOp {
   private void deleteChangeElementsFromDb(ChangeContext ctx, Change.Id id) throws OrmException {
     // Only delete from ReviewDb here; deletion from NoteDb is handled in
     // BatchUpdate.
-    ReviewDb db = unwrap(ctx.getDb());
+    //
+    // This is special. We want to delete exactly the rows that are present in
+    // the database, even when reading everything else from NoteDb, so we need
+    // to bypass the write-only wrapper.
+    ReviewDb db = BatchUpdateReviewDb.unwrap(ctx.getDb());
     db.patchComments().delete(db.patchComments().byChange(id));
     db.patchSetApprovals().delete(db.patchSetApprovals().byChange(id));
     db.patchSets().delete(db.patchSets().byChange(id));
diff --git a/java/com/google/gerrit/server/update/BatchUpdateReviewDb.java b/java/com/google/gerrit/server/update/BatchUpdateReviewDb.java
index 21e1f92581..3b8f871e36 100644
--- a/java/com/google/gerrit/server/update/BatchUpdateReviewDb.java
+++ b/java/com/google/gerrit/server/update/BatchUpdateReviewDb.java
@@ -17,6 +17,7 @@ package com.google.gerrit.server.update;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.server.ChangeAccess;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.reviewdb.server.ReviewDbUtil;
 import com.google.gerrit.reviewdb.server.ReviewDbWrapper;
 import com.google.gwtorm.server.AtomicUpdate;
 
@@ -28,6 +29,14 @@ public class BatchUpdateReviewDb extends ReviewDbWrapper {
     changesWrapper = new BatchUpdateChanges(delegate.changes());
   }
 
+  /** @return the underlying delegate. Supports BatchUpdateReviewDb too. */
+  public static ReviewDb unwrap(ReviewDb db) {
+    if (db instanceof BatchUpdateReviewDb) {
+      db = ((BatchUpdateReviewDb) db).unsafeGetDelegate();
+    }
+    return ReviewDbUtil.unwrapDb(db);
+  }
+
   public ReviewDb unsafeGetDelegate() {
     return delegate;
   }