diff --git a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/Evaluator.java b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/Evaluator.java
index 35fb4bf03cd..dba7403c652 100644
--- a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/Evaluator.java
+++ b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/Evaluator.java
@@ -23,6 +23,6 @@ import org.elasticsearch.common.io.stream.NamedWriteable;
 import org.elasticsearch.search.SearchHit;
 
 public interface Evaluator extends NamedWriteable {
-    
-    public Object evaluate(SearchHit[] hits, RatedQuery intent);
+
+    Object evaluate(SearchHit[] hits, RatedQuery intent);
 }
diff --git a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java
index 1a75247e48d..41168b10329 100644
--- a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java
+++ b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java
@@ -24,7 +24,7 @@ import org.elasticsearch.search.SearchHit;
 /**
  * Classes implementing this interface provide a means to compute the quality of a result list
  * returned by some search.
- * 
+ *
  * RelevancyLevel specifies the type of object determining the relevancy level of some known docid.
  * */
 public interface RankedListQualityMetric extends Evaluator {
@@ -36,5 +36,6 @@ public interface RankedListQualityMetric extends Evaluator {
      * @param hits the result hits as returned by some search
      * @return some metric representing the quality of the result hit list wrt. to relevant doc ids.
      * */
-    public EvalQueryQuality evaluate(SearchHit[] hits, RatedQuery intent);
+    @Override
+    EvalQueryQuality evaluate(SearchHit[] hits, RatedQuery intent);
 }