diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2PrimitiveValueImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2PrimitiveValueImpl.java
index 7fcc93e9f27..dda63d73d94 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2PrimitiveValueImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2PrimitiveValueImpl.java
@@ -34,7 +34,7 @@ public class CSS2PrimitiveValueImpl implements CSSPrimitiveValue {
 
 	private int i = -9999;
 
-	private short primitiveType;
+	private final short primitiveType;
 
 	public CSS2PrimitiveValueImpl(String s) {
 		this.s = s;
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2RGBColorImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2RGBColorImpl.java
index e19194f3e16..55814dba76b 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2RGBColorImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/css2/CSS2RGBColorImpl.java
@@ -24,9 +24,9 @@
  */
 public class CSS2RGBColorImpl implements RGBColor {
 
-	private CSSPrimitiveValue red;
-	private CSSPrimitiveValue green;
-	private CSSPrimitiveValue blue;
+	private final CSSPrimitiveValue red;
+	private final CSSPrimitiveValue green;
+	private final CSSPrimitiveValue blue;
 
 	public CSS2RGBColorImpl(int r, int g, int b) {
 		red = new CSS2PrimitiveValueImpl(r);
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ArrayNodeList.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ArrayNodeList.java
index 9ca59527959..3695f2fd78c 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ArrayNodeList.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ArrayNodeList.java
@@ -21,8 +21,8 @@
 
 public class ArrayNodeList implements NodeList {
 
-	private Object[] elements;
-	private CSSEngine engine;
+	private final Object[] elements;
+	private final CSSEngine engine;
 
 	public ArrayNodeList(List<?> elements, CSSEngine engine) {
 		this(elements.toArray(), engine);
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ElementAdapter.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ElementAdapter.java
index d8e1fd71158..abdd8d7b72f 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ElementAdapter.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/ElementAdapter.java
@@ -37,11 +37,11 @@ public abstract class ElementAdapter implements Element, CSSStylableElement {
 
 	private static final String[] EMPTY_STRING = new String[0];
 
-	private Object nativeWidget;
+	private final Object nativeWidget;
 
 	protected CSSEngine engine;
 
-	private Map <String, CSSStyleDeclaration> defaultStyleDeclarationMap = new HashMap<>();
+	private final Map <String, CSSStyleDeclaration> defaultStyleDeclarationMap = new HashMap<>();
 
 	private CSSExtendedProperties style;
 
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerLazyProviderImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerLazyProviderImpl.java
index b8a2ea06e2c..0a6232380bb 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerLazyProviderImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerLazyProviderImpl.java
@@ -35,7 +35,7 @@ public class CSSPropertyHandlerLazyProviderImpl extends
 AbstractCSSPropertyHandlerProvider {
 
 	// List of package names containing handlers class for properties
-	private List<String> packageNames = new ArrayList<>();
+	private final List<String> packageNames = new ArrayList<>();
 
 	// Map used as a cache for properties handlers found
 	private Map<String, List<ICSSPropertyHandler>> propertyToHandlersMap = new HashMap<>();
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerSimpleProviderImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerSimpleProviderImpl.java
index cf21d655118..6d70ac88aa0 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerSimpleProviderImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/dom/properties/providers/CSSPropertyHandlerSimpleProviderImpl.java
@@ -46,13 +46,13 @@ public class CSSPropertyHandlerSimpleProviderImpl extends
 	 */
 	private static Map<String, Class<? extends ICSSPropertyHandler>> defaultCSSProperties = new HashMap<>();
 
-	private Map<Class<?>, List<ICSSPropertyHandler>> propertiesHandler = new HashMap<>();
+	private final Map<Class<?>, List<ICSSPropertyHandler>> propertiesHandler = new HashMap<>();
 
 	/**
 	 * Custom <code>Map</code> of <code>ICSSPropertyHandler</code> stored
 	 * under a CSS property <code>name</code> key.
 	 */
-	private Map<String, Class<? extends ICSSPropertyHandler>> customCSSProperties = new HashMap<>();
+	private final Map<String, Class<? extends ICSSPropertyHandler>> customCSSProperties = new HashMap<>();
 
 	/**
 	 * True if custom CSS properties is merged with default CSS Properties.
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSComputedStyleImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSComputedStyleImpl.java
index 0c5fc49f0d1..95f7fdd8a1d 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSComputedStyleImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSComputedStyleImpl.java
@@ -29,7 +29,7 @@
  */
 public class CSSComputedStyleImpl extends CSSStyleDeclarationImpl implements CSSStyleDeclaration {
 
-	private List<StyleWrapper> styleRules;
+	private final List<StyleWrapper> styleRules;
 
 	public CSSComputedStyleImpl(List<StyleWrapper> styleRules) {
 		super(null);
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSPropertyImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSPropertyImpl.java
index 0730d50c486..ff00072a8fb 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSPropertyImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSPropertyImpl.java
@@ -26,7 +26,7 @@ public class CSSPropertyImpl implements CSSProperty {
 	 */
 	protected static String IMPORTANT_IDENTIFIER = "important";
 
-	private String name;
+	private final String name;
 	private CSSValue value;
 	private boolean important;
 
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSRuleListImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSRuleListImpl.java
index 4d017511722..d7110c71d1f 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSRuleListImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSRuleListImpl.java
@@ -22,7 +22,7 @@
 
 public class CSSRuleListImpl implements CSSRuleList {
 
-	private List<CSSRule> ruleList;
+	private final List<CSSRule> ruleList;
 
 	public CSSRuleListImpl() {
 		super();
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleDeclarationImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleDeclarationImpl.java
index f075b754cf9..efe3b61a733 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleDeclarationImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleDeclarationImpl.java
@@ -29,8 +29,8 @@
 public class CSSStyleDeclarationImpl extends AbstractCSSNode implements CSSStyleDeclaration {
 
 	private boolean readOnly;
-	private CSSRule parentRule;
-	private List<CSSProperty> properties = new ArrayList<>();
+	private final CSSRule parentRule;
+	private final List<CSSProperty> properties = new ArrayList<>();
 	private CSSPropertyList cssPropertyListView;
 
 	public CSSStyleDeclarationImpl(CSSRule parentRule) {
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleRuleImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleRuleImpl.java
index bf93956db07..01e5822bd4a 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleRuleImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/CSSStyleRuleImpl.java
@@ -27,7 +27,7 @@
 
 public class CSSStyleRuleImpl extends CSSRuleImpl implements CSSStyleRule, ExtendedCSSRule {
 
-	private SelectorList selectors;
+	private final SelectorList selectors;
 	private CSSStyleDeclaration styleDeclaration;
 
 	public CSSStyleRuleImpl(CSSStyleSheet parentStyleSheet, CSSRule parentRule, SelectorList selectors) {
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/DocumentCSSImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/DocumentCSSImpl.java
index 70cf00c0fe8..f9fba83d961 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/DocumentCSSImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/DocumentCSSImpl.java
@@ -40,14 +40,14 @@
  */
 public class DocumentCSSImpl implements ExtendedDocumentCSS {
 
-	private StyleSheetListImpl styleSheetList = new StyleSheetListImpl();
+	private final StyleSheetListImpl styleSheetList = new StyleSheetListImpl();
 
 	/**
 	 * key=selector type, value = CSSStyleDeclaration
 	 */
 	private Map<Integer, List<?>> styleDeclarationMap;
 
-	private List<StyleSheetChangeListener> styleSheetChangeListeners = new ArrayList<>(1);
+	private final List<StyleSheetChangeListener> styleSheetChangeListeners = new ArrayList<>(1);
 
 	@Override
 	public StyleSheetList getStyleSheets() {
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/MediaListImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/MediaListImpl.java
index 12af55e71ec..ea7a6188731 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/MediaListImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/MediaListImpl.java
@@ -23,7 +23,7 @@
 
 public class MediaListImpl implements MediaList {
 
-	private List<String> mediaList;
+	private final List<String> mediaList;
 
 	public MediaListImpl(SACMediaList media) {
 		mediaList = new ArrayList<>();
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/RGBColorImpl.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/RGBColorImpl.java
index 93904893003..5d3df0458e5 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/RGBColorImpl.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/RGBColorImpl.java
@@ -22,9 +22,9 @@
 
 public class RGBColorImpl extends CSSValueImpl implements RGBColor {
 
-	private CSSPrimitiveValue red;
-	private CSSPrimitiveValue green;
-	private CSSPrimitiveValue blue;
+	private final CSSPrimitiveValue red;
+	private final CSSPrimitiveValue green;
+	private final CSSPrimitiveValue blue;
 
 	public RGBColorImpl(LexicalUnit lexicalUnit) {
 		LexicalUnit nextUnit = lexicalUnit.getParameters();
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/AbstractCSSEngine.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/AbstractCSSEngine.java
index d9216f5abb4..61a74c087b3 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/AbstractCSSEngine.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/AbstractCSSEngine.java
@@ -113,12 +113,12 @@ public abstract class AbstractCSSEngine implements CSSEngine {
 	/**
 	 * w3c {@link DocumentCSS}.
 	 */
-	private ExtendedDocumentCSS documentCSS;
+	private final ExtendedDocumentCSS documentCSS;
 
 	/**
 	 * w3c {@link ViewCSS}.
 	 */
-	private ViewCSS viewCSS;
+	private final ViewCSS viewCSS;
 
 	/**
 	 * {@link IElementProvider} used to retrieve w3c Element linked to the
@@ -144,7 +144,7 @@ public abstract class AbstractCSSEngine implements CSSEngine {
 	 */
 	protected List<ICSSPropertyHandlerProvider> propertyHandlerProviders = new ArrayList<>();
 	// for performance hold a map of handlers to singleton list
-	private Map<ICSSPropertyHandler2, List<ICSSPropertyHandler2>> propertyHandler2InstanceMap = new HashMap<>();
+	private final Map<ICSSPropertyHandler2, List<ICSSPropertyHandler2>> propertyHandler2InstanceMap = new HashMap<>();
 
 	private Map<String, String> currentCSSPropertiesApplied;
 
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSElementProvider.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSElementProvider.java
index 9f6e66c0242..db08cd9fc57 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSElementProvider.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSElementProvider.java
@@ -36,7 +36,7 @@ public class RegistryCSSElementProvider implements IElementProvider {
 
 	final private IExtensionRegistry registry;
 
-	private Map<Class<?>, IElementProvider> providerCache = Collections
+	private final Map<Class<?>, IElementProvider> providerCache = Collections
 			.synchronizedMap(new WeakHashMap<>());
 
 	public RegistryCSSElementProvider(IExtensionRegistry registry) {
diff --git a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSPropertyHandlerProvider.java b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSPropertyHandlerProvider.java
index 52f07fb641f..467d6ba2a46 100644
--- a/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSPropertyHandlerProvider.java
+++ b/bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/engine/RegistryCSSPropertyHandlerProvider.java
@@ -48,12 +48,12 @@ public class RegistryCSSPropertyHandlerProvider extends AbstractCSSPropertyHandl
 
 	private static final String PROPERTY_HANDLERS_EXTPOINT = "org.eclipse.e4.ui.css.core.propertyHandler";
 
-	private IExtensionRegistry registry;
+	private final IExtensionRegistry registry;
 	private boolean hasDeprecatedProperties = false; // mild optimization for getCSSProperties()
 
-	private Map<String, Map<String, ICSSPropertyHandler>> propertyHandlerMap = new HashMap<>();
+	private final Map<String, Map<String, ICSSPropertyHandler>> propertyHandlerMap = new HashMap<>();
 	// for performance hold a map of handlers to singleton list
-	private Map<ICSSPropertyHandler, List<ICSSPropertyHandler>> propertyHandlerInstanceMap = new HashMap<>();
+	private final Map<ICSSPropertyHandler, List<ICSSPropertyHandler>> propertyHandlerInstanceMap = new HashMap<>();
 
 	public RegistryCSSPropertyHandlerProvider(IExtensionRegistry registry) {
 		this.registry = registry;
@@ -234,9 +234,9 @@ protected void logError(String message) {
 	}
 
 	private class DeprecatedPropertyHandlerWrapper implements ICSSPropertyHandler {
-		private ICSSPropertyHandler delegate;
-		private String message;
-		private Set<String> logged = new HashSet<>();
+		private final ICSSPropertyHandler delegate;
+		private final String message;
+		private final Set<String> logged = new HashSet<>();
 
 		DeprecatedPropertyHandlerWrapper(ICSSPropertyHandler handler, String message) {
 			delegate = handler;