diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_115.java b/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_115.java
index 920160b539..30479b77d5 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_115.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_115.java
@@ -131,18 +131,18 @@ public class Schema_115 extends SchemaVersion {
     try (Repository git = mgr.openRepository(allUsersName);
         RevWalk rw = new RevWalk(git)) {
       BatchRefUpdate bru = git.getRefDatabase().newBatchUpdate();
-      MetaDataUpdate md = new MetaDataUpdate(GitReferenceUpdated.DISABLED,
-          allUsersName, git, bru);
-      md.getCommitBuilder().setAuthor(serverUser);
-      md.getCommitBuilder().setCommitter(serverUser);
-
       for (Map.Entry<Account.Id, DiffPreferencesInfo> e : imports.entrySet()) {
-        VersionedAccountPreferences p =
-            VersionedAccountPreferences.forUser(e.getKey());
-        p.load(md);
-        storeSection(p.getConfig(), UserConfigSections.DIFF, null,
-            e.getValue(), DiffPreferencesInfo.defaults());
-        p.commit(md);
+        try(MetaDataUpdate md = new MetaDataUpdate(GitReferenceUpdated.DISABLED,
+            allUsersName, git, bru)) {
+          md.getCommitBuilder().setAuthor(serverUser);
+          md.getCommitBuilder().setCommitter(serverUser);
+          VersionedAccountPreferences p =
+              VersionedAccountPreferences.forUser(e.getKey());
+          p.load(md);
+          storeSection(p.getConfig(), UserConfigSections.DIFF, null,
+              e.getValue(), DiffPreferencesInfo.defaults());
+          p.commit(md);
+        }
       }
 
       bru.execute(rw, NullProgressMonitor.INSTANCE);