diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/ParentLastURLClassLoader.java b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/ParentLastURLClassLoader.java
index da2595cb426..d302fa0bfd0 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/ParentLastURLClassLoader.java
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/ParentLastURLClassLoader.java
@@ -1,6 +1,7 @@
 package org.jetbrains.kotlin.gradle.plugin;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.net.URL;
 import java.net.URLClassLoader;
@@ -11,11 +12,13 @@ import java.util.List;
  * This takes a fair bit of doing because java really prefers parent-first.
  * <p/>
  * For those not familiar with class loading trickery, be wary
+ *
+ * http://stackoverflow.com/questions/5445511/how-do-i-create-a-parent-last-child-first-classloader-in-java-or-how-to-overr
  */
 public class ParentLastURLClassLoader extends ClassLoader {
-    private ChildURLClassLoader childClassLoader;
+    private final ChildURLClassLoader childClassLoader;
 
-    public ParentLastURLClassLoader(List<URL> classpath, ClassLoader parent) {
+    public ParentLastURLClassLoader(@NotNull List<URL> classpath, @Nullable ClassLoader parent) {
         super(Thread.currentThread().getContextClassLoader());
 
         URL[] urls = classpath.toArray(new URL[classpath.size()]);
@@ -28,7 +31,8 @@ public class ParentLastURLClassLoader extends ClassLoader {
         try {
             // first we try to find a class inside the child classloader
             return childClassLoader.findClass(name);
-        } catch (ClassNotFoundException e) {
+        }
+        catch (ClassNotFoundException e) {
             // didn't find it, try the parent
             return super.loadClass(name, resolve);
         }
@@ -38,7 +42,7 @@ public class ParentLastURLClassLoader extends ClassLoader {
      * This class allows me to call findClass on a classloader
      */
     private static class FindClassClassLoader extends ClassLoader {
-        public FindClassClassLoader(ClassLoader parent) {
+        public FindClassClassLoader(@Nullable ClassLoader parent) {
             super(parent);
         }
 
@@ -54,9 +58,9 @@ public class ParentLastURLClassLoader extends ClassLoader {
      * We need this because findClass is protected in URLClassLoader
      */
     public static class ChildURLClassLoader extends URLClassLoader {
-        private FindClassClassLoader realParent;
+        private final FindClassClassLoader realParent;
 
-        public ChildURLClassLoader(URL[] urls, FindClassClassLoader realParent) {
+        public ChildURLClassLoader(@NotNull URL[] urls, @NotNull FindClassClassLoader realParent) {
             super(urls, null);
 
             this.realParent = realParent;
@@ -73,7 +77,8 @@ public class ParentLastURLClassLoader extends ClassLoader {
 
             try {
                 return super.findClass(name);
-            } catch (ClassNotFoundException e) {
+            }
+            catch (ClassNotFoundException e) {
                 // if that fails, we ask our real parent classloader to load the class (we give up)
                 return realParent.loadClass(name);
             }