diff --git a/core/src/main/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoader.java b/core/src/main/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoader.java
index 6d3e87d03fa..6ee1f58cf4b 100644
--- a/core/src/main/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoader.java
+++ b/core/src/main/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoader.java
@@ -73,7 +73,7 @@ public class PropertiesSettingsLoader implements SettingsLoader {
     class NoDuplicatesProperties extends Properties {
         @Override
         public synchronized Object put(Object key, Object value) {
-            Object previousValue = super.put(key, value);
+            final Object previousValue = super.put(key, value);
             if (previousValue != null) {
                 throw new ElasticsearchParseException(
                         "duplicate settings key [{}] found, previous value [{}], current value [{}]",
diff --git a/core/src/test/java/org/elasticsearch/common/settings/loader/JsonSettingsLoaderTests.java b/core/src/test/java/org/elasticsearch/common/settings/loader/JsonSettingsLoaderTests.java
index fadbd2bee46..154ef8ee039 100644
--- a/core/src/test/java/org/elasticsearch/common/settings/loader/JsonSettingsLoaderTests.java
+++ b/core/src/test/java/org/elasticsearch/common/settings/loader/JsonSettingsLoaderTests.java
@@ -31,8 +31,8 @@ import static org.hamcrest.Matchers.equalTo;
 public class JsonSettingsLoaderTests extends ESTestCase {
 
     public void testSimpleJsonSettings() throws Exception {
-        String json = "/org/elasticsearch/common/settings/loader/test-settings.json";
-        Settings settings = settingsBuilder()
+        final String json = "/org/elasticsearch/common/settings/loader/test-settings.json";
+        final Settings settings = settingsBuilder()
                 .loadFromStream(json, getClass().getResourceAsStream(json))
                 .build();
 
diff --git a/core/src/test/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoaderTests.java b/core/src/test/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoaderTests.java
index ab96f763a88..c13ae7cc68b 100644
--- a/core/src/test/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoaderTests.java
+++ b/core/src/test/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoaderTests.java
@@ -50,7 +50,7 @@ public class PropertiesSettingsLoaderTests extends ESTestCase {
     }
 
     public void testThatNoDuplicatesPropertiesDoesNotAcceptNullValues() {
-        PropertiesSettingsLoader.NoDuplicatesProperties properties = loader.new NoDuplicatesProperties();
+        final PropertiesSettingsLoader.NoDuplicatesProperties properties = loader.new NoDuplicatesProperties();
         expectThrows(NullPointerException.class, () -> properties.put("key", null));
     }
 
diff --git a/core/src/test/java/org/elasticsearch/common/settings/loader/YamlSettingsLoaderTests.java b/core/src/test/java/org/elasticsearch/common/settings/loader/YamlSettingsLoaderTests.java
index 62350f55023..2e2a187da0b 100644
--- a/core/src/test/java/org/elasticsearch/common/settings/loader/YamlSettingsLoaderTests.java
+++ b/core/src/test/java/org/elasticsearch/common/settings/loader/YamlSettingsLoaderTests.java
@@ -31,8 +31,8 @@ import static org.hamcrest.Matchers.equalTo;
 public class YamlSettingsLoaderTests extends ESTestCase {
 
     public void testSimpleYamlSettings() throws Exception {
-        String yaml = "/org/elasticsearch/common/settings/loader/test-settings.yml";
-        Settings settings = settingsBuilder()
+        final String yaml = "/org/elasticsearch/common/settings/loader/test-settings.yml";
+        final Settings settings = settingsBuilder()
                 .loadFromStream(yaml, getClass().getResourceAsStream(yaml))
                 .build();