diff --git a/pom.xml b/pom.xml
index 12779cc6..e1b9a1dd 100644
--- a/pom.xml
+++ b/pom.xml
@@ -198,7 +198,7 @@
         <dependency>
             <groupId>me.main__.util</groupId>
             <artifactId>SerializationConfig</artifactId>
-            <version>1.5</version>
+            <version>1.6</version>
             <type>jar</type>
             <scope>compile</scope>
         </dependency>
diff --git a/src/main/java/com/onarandombox/MultiverseCore/MVWorld.java b/src/main/java/com/onarandombox/MultiverseCore/MVWorld.java
index 782379b4..cddc4238 100644
--- a/src/main/java/com/onarandombox/MultiverseCore/MVWorld.java
+++ b/src/main/java/com/onarandombox/MultiverseCore/MVWorld.java
@@ -341,7 +341,7 @@ public class MVWorld extends SerializationConfig implements MultiverseWorld {
     private String alias;
     @Property(serializor = EnumPropertySerializor.class, description = "Sorry, 'color' must be a valid color-name.")
     private EnglishChatColor color;
-    @Property(description = "Sorry, 'pvp' must either be: true or false.")
+    @Property(description = "Sorry, 'pvp' must either be: true or false.", virtualType = Boolean.class)
     private VirtualProperty<Boolean> pvp = new VirtualProperty<Boolean>() {
         @Override
         public void set(Boolean newValue) {
@@ -359,7 +359,8 @@ public class MVWorld extends SerializationConfig implements MultiverseWorld {
     private String respawnWorld;
     @Property(validator = AllowWeatherPropertyValidator.class, description = "Sorry, this must either be: true or false.")
     private boolean allowWeather;
-    @Property(serializor = DifficultyPropertySerializor.class, description = "Difficulty must be set as one of the following: peaceful easy normal hard")
+    @Property(serializor = DifficultyPropertySerializor.class, virtualType = Difficulty.class,
+            description = "Difficulty must be set as one of the following: peaceful easy normal hard")
     private VirtualProperty<Difficulty> difficulty = new VirtualProperty<Difficulty>() {
         @Override
         public void set(Difficulty newValue) {
@@ -388,7 +389,7 @@ public class MVWorld extends SerializationConfig implements MultiverseWorld {
     private GameMode gameMode;
     @Property
     private boolean keepSpawnLoaded;
-    @Property(description = "Sorry, this must either be: true or false.")
+    @Property(description = "Sorry, this must either be: true or false.", virtualType = Boolean.class)
     private VirtualProperty<Boolean> keepSpawnInMemory = new VirtualProperty<Boolean>() {
         @Override
         public void set(Boolean newValue) {
@@ -403,7 +404,7 @@ public class MVWorld extends SerializationConfig implements MultiverseWorld {
     };
     @Property
     private SpawnLocation spawnLocation;
-    @Property(validator = SpawnLocationPropertyValidator.class,
+    @Property(validator = SpawnLocationPropertyValidator.class, virtualType = Location.class,
             description = "There is no help available for this variable. Go bug Rigby90 about it.")
     private VirtualProperty<Location> spawn = new VirtualProperty<Location>() {
         @Override
@@ -429,7 +430,8 @@ public class MVWorld extends SerializationConfig implements MultiverseWorld {
     @Property
     private List<String> worldBlacklist;
     @SuppressWarnings("unused") // it IS used!
-    @Property(serializor = TimePropertySerializor.class, description = "Set the time to whatever you want! (Will NOT freeze time)")
+    @Property(serializor = TimePropertySerializor.class, virtualType = Long.class,
+            description = "Set the time to whatever you want! (Will NOT freeze time)")
     private VirtualProperty<Long> time = new VirtualProperty<Long>() {
         @Override
         public void set(Long newValue) {
diff --git a/src/test/java/com/onarandombox/MultiverseCore/test/TestModifyCommand.java b/src/test/java/com/onarandombox/MultiverseCore/test/TestModifyCommand.java
new file mode 100644
index 00000000..6eff3363
--- /dev/null
+++ b/src/test/java/com/onarandombox/MultiverseCore/test/TestModifyCommand.java
@@ -0,0 +1,61 @@
+package com.onarandombox.MultiverseCore.test;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import org.bukkit.Server;
+import org.bukkit.World.Environment;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import com.onarandombox.MultiverseCore.MultiverseCore;
+import com.onarandombox.MultiverseCore.api.MultiverseWorld;
+import com.onarandombox.MultiverseCore.test.utils.TestInstanceCreator;
+
+
+@RunWith(PowerMockRunner.class)
+@PrepareForTest({ MultiverseCore.class, PluginDescriptionFile.class })
+public class TestModifyCommand {
+    TestInstanceCreator creator;
+    Server mockServer;
+    MultiverseCore core;
+    CommandSender mockCommandSender;
+
+    @Before
+    public void setUp() throws Exception {
+        creator = new TestInstanceCreator();
+        assertTrue(creator.setUp());
+        mockServer = creator.getServer();
+        mockCommandSender = creator.getCommandSender();
+        core = creator.getCore();
+
+        // create world
+        assertTrue(core.getMVWorldManager().addWorld("world", Environment.NORMAL, null, null, null, null));
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        creator.tearDown();
+    }
+
+    @Test
+    public void testSetHidden() {
+        Command cmd = mock(Command.class);
+        when(cmd.getName()).thenReturn("mv");
+
+        MultiverseWorld world = core.getMVWorldManager().getMVWorld("world");
+        assertNotNull(world);
+
+        assertFalse(world.isHidden()); // ensure it's not hidden now
+        assertTrue(core.onCommand(mockCommandSender, cmd, "", // run the command
+                new String[] { "modify", "set", "hidden", "true", "world" }));
+        assertTrue(world.isHidden()); // test if it worked
+    }
+}