diff --git a/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java b/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java
index a474c00..af85973 100644
--- a/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java
+++ b/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java
@@ -53,7 +53,7 @@
  */
 public class GetCodeOwnersForPathInBranch extends AbstractGetCodeOwnersForPath
     implements RestReadView<CodeOwnersInBranchCollection.PathResource> {
-  private GitRepositoryManager repoManager;
+  private final GitRepositoryManager repoManager;
   private String revision;
 
   @Option(name = "-revision", usage = "revision from which the code owner configs should be read")