diff --git a/java/com/google/gerrit/server/git/validators/MergeValidationListener.java b/java/com/google/gerrit/server/git/validators/MergeValidationListener.java
index b47d7d6..79d53ac 100644
--- a/java/com/google/gerrit/server/git/validators/MergeValidationListener.java
+++ b/java/com/google/gerrit/server/git/validators/MergeValidationListener.java
@@ -19,6 +19,7 @@
 import com.google.gerrit.extensions.annotations.ExtensionPoint;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.git.CodeReviewCommit;
+import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
 import com.google.gerrit.server.project.ProjectState;
 import org.eclipse.jgit.lib.Repository;
 
@@ -33,6 +34,7 @@
    * Validate a commit before it is merged.
    *
    * @param repo the repository
+   * @param revWalk the rev walk
    * @param commit commit details
    * @param destProject the destination project
    * @param destBranch the destination branch
@@ -42,6 +44,7 @@
    */
   void onPreMerge(
       Repository repo,
+      CodeReviewRevWalk revWalk,
       CodeReviewCommit commit,
       ProjectState destProject,
       BranchNameKey destBranch,
diff --git a/java/com/google/gerrit/server/git/validators/MergeValidators.java b/java/com/google/gerrit/server/git/validators/MergeValidators.java
index 4e5ce0c..cbaa121 100644
--- a/java/com/google/gerrit/server/git/validators/MergeValidators.java
+++ b/java/com/google/gerrit/server/git/validators/MergeValidators.java
@@ -35,6 +35,7 @@
 import com.google.gerrit.server.config.PluginConfig;
 import com.google.gerrit.server.config.ProjectConfigEntry;
 import com.google.gerrit.server.git.CodeReviewCommit;
+import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
 import com.google.gerrit.server.permissions.GlobalPermission;
 import com.google.gerrit.server.permissions.PermissionBackend;
 import com.google.gerrit.server.permissions.PermissionBackendException;
@@ -51,7 +52,6 @@
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.revwalk.RevWalk;
 
 /**
  * Collection of validators that run inside Gerrit before a change is submitted. The main purpose is
@@ -92,6 +92,7 @@
    */
   public void validatePreMerge(
       Repository repo,
+      CodeReviewRevWalk revWalk,
       CodeReviewCommit commit,
       ProjectState destProject,
       BranchNameKey destBranch,
@@ -106,7 +107,7 @@
             groupValidatorFactory.create());
 
     for (MergeValidationListener validator : validators) {
-      validator.onPreMerge(repo, commit, destProject, destBranch, patchSetId, caller);
+      validator.onPreMerge(repo, revWalk, commit, destProject, destBranch, patchSetId, caller);
     }
   }
 
@@ -168,11 +169,12 @@
 
     @Override
     public void onPreMerge(
-        final Repository repo,
-        final CodeReviewCommit commit,
-        final ProjectState destProject,
-        final BranchNameKey destBranch,
-        final PatchSet.Id patchSetId,
+        Repository repo,
+        CodeReviewRevWalk revWalk,
+        CodeReviewCommit commit,
+        ProjectState destProject,
+        BranchNameKey destBranch,
+        PatchSet.Id patchSetId,
         IdentifiedUser caller)
         throws MergeValidationException {
       if (RefNames.REFS_CONFIG.equals(destBranch.branch())) {
@@ -260,6 +262,7 @@
     @Override
     public void onPreMerge(
         Repository repo,
+        CodeReviewRevWalk revWalk,
         CodeReviewCommit commit,
         ProjectState destProject,
         BranchNameKey destBranch,
@@ -267,7 +270,7 @@
         IdentifiedUser caller)
         throws MergeValidationException {
       mergeValidationListeners.runEach(
-          l -> l.onPreMerge(repo, commit, destProject, destBranch, patchSetId, caller),
+          l -> l.onPreMerge(repo, revWalk, commit, destProject, destBranch, patchSetId, caller),
           MergeValidationException.class);
     }
   }
@@ -294,6 +297,7 @@
     @Override
     public void onPreMerge(
         Repository repo,
+        CodeReviewRevWalk revWalk,
         CodeReviewCommit commit,
         ProjectState destProject,
         BranchNameKey destBranch,
@@ -316,8 +320,9 @@
         throw new MergeValidationException("account validation unavailable");
       }
 
-      try (RevWalk rw = new RevWalk(repo)) {
-        List<String> errorMessages = accountValidator.validate(accountId, repo, rw, null, commit);
+      try {
+        List<String> errorMessages =
+            accountValidator.validate(accountId, repo, revWalk, null, commit);
         if (!errorMessages.isEmpty()) {
           throw new MergeValidationException(
               "invalid account configuration: " + Joiner.on("; ").join(errorMessages));
@@ -345,6 +350,7 @@
     @Override
     public void onPreMerge(
         Repository repo,
+        CodeReviewRevWalk revWalk,
         CodeReviewCommit commit,
         ProjectState destProject,
         BranchNameKey destBranch,
diff --git a/java/com/google/gerrit/server/submit/MergeOp.java b/java/com/google/gerrit/server/submit/MergeOp.java
index 58b0c8e..8a293a4 100644
--- a/java/com/google/gerrit/server/submit/MergeOp.java
+++ b/java/com/google/gerrit/server/submit/MergeOp.java
@@ -864,7 +864,8 @@
 
       MergeValidators mergeValidators = mergeValidatorsFactory.create();
       try {
-        mergeValidators.validatePreMerge(or.repo, commit, or.project, destBranch, ps.id(), caller);
+        mergeValidators.validatePreMerge(
+            or.repo, or.rw, commit, or.project, destBranch, ps.id(), caller);
       } catch (MergeValidationException mve) {
         commitStatus.problem(changeId, mve.getMessage());
         continue;
diff --git a/plugins/hooks b/plugins/hooks
index 7ed555f..ad4f877 160000
--- a/plugins/hooks
+++ b/plugins/hooks
@@ -1 +1 @@
-Subproject commit 7ed555fe88f4be028acbfd5c245ac78537ac3666
+Subproject commit ad4f877749928b69ef94b62176c5797f6648887d