diff --git a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
index fe723c9f..f8ef65bc 100644
--- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
@@ -48,7 +48,7 @@
 public final class JavaPluginLoader implements PluginLoader {
     final Server server;
     private final Pattern[] fileFilters = new Pattern[] { Pattern.compile("\\.jar$"), };
-    private final Map<String, Class<?>> classes = new HashMap<String, Class<?>>();
+    private final Map<String, Class<?>> classes = new java.util.concurrent.ConcurrentHashMap<String, Class<?>>(); // Spigot
     private final Map<String, PluginClassLoader> loaders = new LinkedHashMap<String, PluginClassLoader>();
     public static final CustomTimingsHandler pluginParentTimer = new CustomTimingsHandler("** Plugins"); // Spigot
 
diff --git a/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java b/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
index 13f86338..4cffa137 100644
--- a/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
@@ -17,7 +17,7 @@
  */
 final class PluginClassLoader extends URLClassLoader {
     private final JavaPluginLoader loader;
-    private final Map<String, Class<?>> classes = new HashMap<String, Class<?>>();
+    private final Map<String, Class<?>> classes = new java.util.concurrent.ConcurrentHashMap<String, Class<?>>(); // Spigot
     private final PluginDescriptionFile description;
     private final File dataFolder;
     private final File file;
@@ -25,6 +25,30 @@ final class PluginClassLoader extends URLClassLoader {
     private JavaPlugin pluginInit;
     private IllegalStateException pluginState;
 
+    // Spigot Start
+    static
+    {
+        try
+        {
+            java.lang.reflect.Method method = ClassLoader.class.getDeclaredMethod( "registerAsParallelCapable" );
+            if ( method != null )
+            {
+                boolean oldAccessible = method.isAccessible();
+                method.setAccessible( true );
+                method.invoke( null );
+                method.setAccessible( oldAccessible );
+                org.bukkit.Bukkit.getLogger().log( java.util.logging.Level.INFO, "Set PluginClassLoader as parallel capable" );
+            }
+        } catch ( NoSuchMethodException ex )
+        {
+            // Ignore
+        } catch ( Exception ex )
+        {
+            org.bukkit.Bukkit.getLogger().log( java.util.logging.Level.WARNING, "Error setting PluginClassLoader as parallel capable", ex );
+        }
+    }
+    // Spigot End
+    
     PluginClassLoader(final JavaPluginLoader loader, final ClassLoader parent, final PluginDescriptionFile description, final File dataFolder, final File file) throws InvalidPluginException, MalformedURLException {
         super(new URL[] {file.toURI().toURL()}, parent);
         Validate.notNull(loader, "Loader cannot be null");