diff --git a/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java b/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java
index f5278229..c6598ad9 100644
--- a/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java
+++ b/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java
@@ -65,9 +65,9 @@
  */
 @Named
 public class DefaultCheckstyleExecutor extends AbstractLogEnabled implements CheckstyleExecutor {
-    private ResourceManager locator;
+    private final ResourceManager locator;
 
-    private ResourceManager licenseLocator;
+    private final ResourceManager licenseLocator;
 
     @Inject
     public DefaultCheckstyleExecutor(