diff --git a/java/com/google/gerrit/plugins/codeowners/restapi/RenameEmail.java b/java/com/google/gerrit/plugins/codeowners/restapi/RenameEmail.java
index 8df9a34..e8092b3 100644
--- a/java/com/google/gerrit/plugins/codeowners/restapi/RenameEmail.java
+++ b/java/com/google/gerrit/plugins/codeowners/restapi/RenameEmail.java
@@ -56,7 +56,7 @@
 @Singleton
 public class RenameEmail implements RestModifyView<BranchResource, RenameEmailInput> {
   @VisibleForTesting
-  public static String DEFAULT_COMMIT_MESSAGE = "Rename email in code owner config files";
+  public static final String DEFAULT_COMMIT_MESSAGE = "Rename email in code owner config files";
 
   private final Provider<CurrentUser> currentUser;
   private final PermissionBackend permissionBackend;