diff --git a/commons-testing-junit4-mongodb/src/main/java/org/apache/commons/testing/junit4/mongodb/MongoDbTestRule.java b/commons-testing-junit4-mongodb/src/main/java/org/apache/commons/testing/junit4/mongodb/MongoDbTestRule.java
index 9873466..617df65 100644
--- a/commons-testing-junit4-mongodb/src/main/java/org/apache/commons/testing/junit4/mongodb/MongoDbTestRule.java
+++ b/commons-testing-junit4-mongodb/src/main/java/org/apache/commons/testing/junit4/mongodb/MongoDbTestRule.java
@@ -70,7 +70,7 @@
         this(portSystemPropertyName, DEFAULT_MONGODB_VERSION);
     }
 
-    public MongoDbTestRule(final String portSystemPropertyName, Main mongoDbVersion) {
+    public MongoDbTestRule(final String portSystemPropertyName, final Main mongoDbVersion) {
         this.portSystemPropertyName = Objects.requireNonNull(portSystemPropertyName, "portSystemPropertyName");
         this.mongoDbVersion = mongoDbVersion;
     }