diff --git a/src/main/java/noppes/npcs/CustomNpcs.java b/src/main/java/noppes/npcs/CustomNpcs.java
index 6ce129262..8192c065a 100644
--- a/src/main/java/noppes/npcs/CustomNpcs.java
+++ b/src/main/java/noppes/npcs/CustomNpcs.java
@@ -13,9 +13,11 @@ import cpw.mods.fml.common.event.FMLServerStoppedEvent;
 import cpw.mods.fml.common.network.NetworkRegistry;
 import cpw.mods.fml.common.registry.EntityRegistry;
 import cpw.mods.fml.relauncher.Side;
+import cpw.mods.fml.relauncher.SideOnly;
 import foxz.command.CommandNoppes;
 import io.github.somehussar.janinoloader.api.IDynamicCompiler;
 import io.github.somehussar.janinoloader.api.IDynamicCompilerBuilder;
+import io.github.somehussar.janinoloader.api.delegates.LoadClassCondition;
 import kamkeel.npcs.addon.AddonManager;
 import kamkeel.npcs.command.CommandKamkeel;
 import kamkeel.npcs.command.profile.CommandProfile;
@@ -98,9 +100,16 @@ import noppes.npcs.entity.old.EntityNpcNagaFemale;
 import noppes.npcs.entity.old.EntityNpcNagaMale;
 import noppes.npcs.entity.old.EntityNpcSkeleton;
 import noppes.npcs.scripted.NpcAPI;
+import somehussar.janino.AdvancedClassFilter;
 
 import java.io.File;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
+import java.util.function.Consumer;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 @Mod(modid = "customnpcs", name = "CustomNPC+", version = "1.10.2")
 public class CustomNpcs {
@@ -139,12 +148,21 @@ public class CustomNpcs {
 
     public static MinecraftServer Server;
 
+    private static IDynamicCompiler jls;
+    @SideOnly(Side.CLIENT)
+    private static IDynamicCompiler clientJaninoCompiler;
+    @SideOnly(Side.CLIENT)
+    private final static Set<Consumer<AdvancedClassFilter>> clientClassFilterConsumer = new HashSet<>();
+
+    @SideOnly(Side.CLIENT)
+    public static void addClassesToClientClassFilter(Consumer<AdvancedClassFilter> consumer) {
+        clientClassFilterConsumer.add(consumer);
+    }
+
     public CustomNpcs() {
         instance = this;
     }
 
-    private static IDynamicCompiler jls;
-
     public static IDynamicCompiler getDynamicCompiler() {
         if (jls == null) {
             jls = IDynamicCompilerBuilder.createBuilder().getCompiler();
@@ -153,6 +171,26 @@ public class CustomNpcs {
         return jls;
     }
 
+    @SideOnly(Side.CLIENT)
+    public static IDynamicCompiler getClientCompiler() {
+
+        if (clientJaninoCompiler == null) {
+            AdvancedClassFilter filter = new AdvancedClassFilter()
+                .addRegexes("noppes\\.npcs\\.api\\..*")
+                .banRegexes(".*ClassLoader.*",
+                    ".*File*.");
+
+            for (Consumer<AdvancedClassFilter> consumer : clientClassFilterConsumer) {
+                consumer.accept(filter);
+            }
+
+
+            clientJaninoCompiler = IDynamicCompilerBuilder.createBuilder().setClassFilter(filter).getCompiler();
+        }
+
+        return clientJaninoCompiler;
+    }
+
     @EventHandler
     public void load(FMLPreInitializationEvent ev) {
         PacketHandler.Instance = new PacketHandler();
diff --git a/src/main/java/somehussar/janino/AdvancedClassFilter.java b/src/main/java/somehussar/janino/AdvancedClassFilter.java
new file mode 100644
index 000000000..fb1fac6e8
--- /dev/null
+++ b/src/main/java/somehussar/janino/AdvancedClassFilter.java
@@ -0,0 +1,54 @@
+package somehussar.janino;
+
+import io.github.somehussar.janinoloader.api.delegates.LoadClassCondition;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+public class AdvancedClassFilter implements LoadClassCondition {
+
+    private final Set<String> allowedClasses = new HashSet<>();
+    private final Set<Pattern> allowedWildCards = new HashSet<>();
+    private final Set<String> bannedClasses = new HashSet<>();
+    private final Set<Pattern> bannedWildCards = new HashSet<>();
+
+    public AdvancedClassFilter() {
+        addClasses("java.io.Serializable", "java.util.Iterator");
+        addRegexes("java\\.lang\\..");
+    }
+
+    public AdvancedClassFilter addRegexes(String... classRegexes) {
+        allowedWildCards.addAll(Arrays.stream(classRegexes).map(Pattern::compile).collect(Collectors.toList()));
+        return this;
+    }
+    public AdvancedClassFilter banRegexes(String... classRegexes) {
+        bannedWildCards.addAll(Arrays.stream(classRegexes).map(Pattern::compile).collect(Collectors.toList()));
+        return this;
+    }
+    public AdvancedClassFilter addClasses(String... classPath) {
+        allowedClasses.addAll(Arrays.asList(classPath));
+        return this;
+    }
+    public AdvancedClassFilter banClasses(String... classPath) {
+        bannedClasses.addAll(Arrays.asList(classPath));
+        return this;
+    }
+
+
+    @Override
+    public boolean isValid(String name) {
+        if (bannedClasses.contains(name))
+            return false;
+        if (bannedWildCards.stream().anyMatch(pattern -> pattern.matcher(name).matches()))
+            return false;
+
+        if (name.startsWith("java.lang")) return true;
+
+        if (allowedClasses.contains(name)) return true;
+
+        return allowedWildCards.stream().anyMatch(pattern -> pattern.matcher(name).matches());
+    }
+}