diff --git a/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsGlobalBlock.java b/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsGlobalBlock.java
index 6948fe1c52a..a1910eea822 100644
--- a/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsGlobalBlock.java
+++ b/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsGlobalBlock.java
@@ -13,14 +13,10 @@ import java.util.List;
  * Represents a JavaScript block in the global scope.
  */
 public class JsGlobalBlock extends JsBlock {
-
-  public JsGlobalBlock() {
-  }
-
-  @Override
-  public boolean isGlobalBlock() {
-    return true;
-  }
+    @Override
+    public boolean isGlobalBlock() {
+        return true;
+    }
 
     @NotNull
     @Override
diff --git a/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsVisitorWithContextImpl.java b/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsVisitorWithContextImpl.java
index d2b0dc8a816..a03e26c2502 100644
--- a/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsVisitorWithContextImpl.java
+++ b/js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsVisitorWithContextImpl.java
@@ -14,7 +14,7 @@
 
 package org.jetbrains.kotlin.js.backend.ast;
 
-/**
+/*
  * Taken from GWT project with modifications.
  * Original:
  *  repository: https://gwt.googlesource.com/gwt
@@ -33,15 +33,15 @@ import java.util.*;
  */
 public class JsVisitorWithContextImpl extends JsVisitorWithContext {
 
-    protected final Stack<JsContext<JsStatement>> statementContexts = new Stack<JsContext<JsStatement>>();
+    protected final Stack<JsContext<JsStatement>> statementContexts = new Stack<>();
 
     public class ListContext<T extends JsNode> extends JsContext<T> {
         private List<T> nodes;
         private int index;
 
         // Those are reset in every iteration of traverse()
-        private final List<T> previous = new SmartList<T>();
-        private final List<T> next = new SmartList<T>();
+        private final List<T> previous = new SmartList<>();
+        private final List<T> next = new SmartList<>();
         private boolean removed = false;
 
         @Override
@@ -138,7 +138,7 @@ public class JsVisitorWithContextImpl extends JsVisitorWithContext {
         }
     }
 
-    protected static void checkReplacement(@SuppressWarnings("UnusedParameters") JsNode origNode, JsNode newNode) {
+    private static void checkReplacement(@SuppressWarnings("UnusedParameters") JsNode origNode, JsNode newNode) {
         if (newNode == null) throw new RuntimeException("Cannot replace with null");
     }
 
@@ -154,7 +154,7 @@ public class JsVisitorWithContextImpl extends JsVisitorWithContext {
 
     @Override
     protected <T extends JsStatement> JsStatement doAcceptStatement(T statement) {
-        List<JsStatement> statements = new SmartList<JsStatement>(statement);
+        List<JsStatement> statements = new SmartList<>(statement);
         doAcceptStatementList(statements);
 
         if (statements.size() == 1) {
@@ -166,7 +166,7 @@ public class JsVisitorWithContextImpl extends JsVisitorWithContext {
 
     @Override
     protected void doAcceptStatementList(List<JsStatement> statements) {
-        ListContext<JsStatement> context = new ListContext<JsStatement>();
+        ListContext<JsStatement> context = new ListContext<>();
         statementContexts.push(context);
         context.traverse(statements);
         statementContexts.pop();
diff --git a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/context/NamingContext.kt b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/context/NamingContext.kt
index 0ec08ef96db..6b74625a7f4 100644
--- a/js/js.inliner/src/org/jetbrains/kotlin/js/inline/context/NamingContext.kt
+++ b/js/js.inliner/src/org/jetbrains/kotlin/js/inline/context/NamingContext.kt
@@ -18,16 +18,12 @@ package org.jetbrains.kotlin.js.inline.context
 
 import org.jetbrains.kotlin.js.backend.ast.*
 import org.jetbrains.kotlin.js.backend.ast.metadata.synthetic
-
-import java.util.ArrayList
-import java.util.IdentityHashMap
-
-import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
 import org.jetbrains.kotlin.js.inline.util.replaceNames
+import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
 
 class NamingContext(private val statementContext: JsContext<JsStatement>) {
-    private val renamings = IdentityHashMap<JsName, JsExpression>()
-    private val declarations = ArrayList<JsVars>()
+    private val renamings = mutableMapOf<JsName, JsExpression>()
+    private val declarations = mutableListOf<JsVars>()
     private var addedDeclarations = false
 
     fun applyRenameTo(target: JsNode): JsNode {