diff --git a/src/main/java/de/studiocode/invgui/item/itembuilder/ItemBuilder.java b/src/main/java/de/studiocode/invgui/item/itembuilder/ItemBuilder.java
index 75840fc..6ceaf1e 100644
--- a/src/main/java/de/studiocode/invgui/item/itembuilder/ItemBuilder.java
+++ b/src/main/java/de/studiocode/invgui/item/itembuilder/ItemBuilder.java
@@ -5,7 +5,8 @@ import com.mojang.authlib.properties.Property;
 import com.mojang.authlib.properties.PropertyMap;
 import de.studiocode.invgui.util.MojangApiUtils;
 import de.studiocode.invgui.util.Pair;
-import de.studiocode.invgui.util.ReflectionUtils;
+import de.studiocode.invgui.util.reflection.ReflectionRegistry;
+import de.studiocode.invgui.util.reflection.ReflectionUtils;
 import de.studiocode.invgui.window.impl.BaseWindow;
 import org.bukkit.Material;
 import org.bukkit.enchantments.Enchantment;
@@ -54,7 +55,7 @@ public class ItemBuilder implements Cloneable {
         if (itemMeta instanceof Damageable) ((Damageable) itemMeta).setDamage(damage);
         if (customModelData != -1) itemMeta.setCustomModelData(customModelData);
         if (displayName != null) itemMeta.setDisplayName(displayName);
-        if (gameProfile != null) ReflectionUtils.setValueOfDeclaredField(itemMeta, "profile", gameProfile);
+        if (gameProfile != null) ReflectionUtils.setFieldValue(ReflectionRegistry.CB_CRAFT_META_SKULL_PROFILE_FIELD, itemMeta, gameProfile);
         enchantments.forEach((enchantment, pair) -> itemMeta.addEnchant(enchantment, pair.getFirst(), pair.getSecond()));
         itemMeta.addItemFlags(itemFlags.toArray(new ItemFlag[0]));
         itemMeta.setLore(lore);
diff --git a/src/main/java/de/studiocode/invgui/util/ReflectionUtils.java b/src/main/java/de/studiocode/invgui/util/ReflectionUtils.java
deleted file mode 100644
index 51cad2a..0000000
--- a/src/main/java/de/studiocode/invgui/util/ReflectionUtils.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package de.studiocode.invgui.util;
-
-import java.lang.reflect.Field;
-
-public class ReflectionUtils {
-    
-    public static void setValueOfDeclaredField(Object obj, String fieldName, Object value) {
-        try {
-            Class<?> clazz = obj.getClass();
-            Field field = clazz.getDeclaredField(fieldName);
-            boolean accessible = field.isAccessible();
-            field.setAccessible(true);
-            field.set(obj, value);
-            field.setAccessible(accessible);
-        } catch (NoSuchFieldException | IllegalAccessException e) {
-            e.printStackTrace();
-        }
-    }
-    
-}
diff --git a/src/main/java/de/studiocode/invgui/util/reflection/ReflectionRegistry.java b/src/main/java/de/studiocode/invgui/util/reflection/ReflectionRegistry.java
new file mode 100644
index 0000000..0bdae0c
--- /dev/null
+++ b/src/main/java/de/studiocode/invgui/util/reflection/ReflectionRegistry.java
@@ -0,0 +1,19 @@
+package de.studiocode.invgui.util.reflection;
+
+import java.lang.reflect.Field;
+
+import static de.studiocode.invgui.util.reflection.ReflectionUtils.getCBClass;
+import static de.studiocode.invgui.util.reflection.ReflectionUtils.getField;
+
+public class ReflectionRegistry {
+    
+    public static final String NET_MINECRAFT_SERVER_PACKAGE_PATH = ReflectionUtils.getNMS();
+    public static final String CRAFT_BUKKIT_PACKAGE_PATH = ReflectionUtils.getCB();
+    
+    // Classes
+    public static final Class<?> CB_CRAFT_META_SKULL_CLASS = getCBClass("inventory.CraftMetaSkull");
+    
+    // Fields
+    public static final Field CB_CRAFT_META_SKULL_PROFILE_FIELD = getField(CB_CRAFT_META_SKULL_CLASS, true, "profile");
+
+}
diff --git a/src/main/java/de/studiocode/invgui/util/reflection/ReflectionUtils.java b/src/main/java/de/studiocode/invgui/util/reflection/ReflectionUtils.java
new file mode 100644
index 0000000..0e5d725
--- /dev/null
+++ b/src/main/java/de/studiocode/invgui/util/reflection/ReflectionUtils.java
@@ -0,0 +1,86 @@
+package de.studiocode.invgui.util.reflection;
+
+import org.bukkit.Bukkit;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+import static de.studiocode.invgui.util.reflection.ReflectionRegistry.CRAFT_BUKKIT_PACKAGE_PATH;
+import static de.studiocode.invgui.util.reflection.ReflectionRegistry.NET_MINECRAFT_SERVER_PACKAGE_PATH;
+
+public class ReflectionUtils {
+    
+    protected static String getCB() {
+        String path = Bukkit.getServer().getClass().getPackage().getName();
+        String version = path.substring(path.lastIndexOf(".") + 1);
+        return "org.bukkit.craftbukkit." + version + ".";
+    }
+    
+    protected static String getNMS() {
+        String path = Bukkit.getServer().getClass().getPackage().getName();
+        String version = path.substring(path.lastIndexOf(".") + 1);
+        return "net.minecraft.server." + version + ".";
+    }
+    
+    public static Class<?> getNMSClass(String path) {
+        try {
+            return Class.forName(NET_MINECRAFT_SERVER_PACKAGE_PATH + path);
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
+    public static Class<?> getCBClass(String path) {
+        try {
+            return Class.forName(CRAFT_BUKKIT_PACKAGE_PATH + path);
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
+    public static Field getField(Class<?> clazz, boolean declared, String name) {
+        try {
+            Field field = declared ? clazz.getDeclaredField(name) : clazz.getField(name);
+            if (declared) field.setAccessible(true);
+            return field;
+        } catch (NoSuchFieldException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
+    public static Constructor<?> getConstructor(Class<?> clazz, boolean declared, Class<?> parameterTypes) {
+        try {
+            return declared ? clazz.getDeclaredConstructor(parameterTypes) : clazz.getConstructor(parameterTypes);
+        } catch (NoSuchMethodException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
+    public static Method getMethod(Class<?> clazz, boolean declared, String name, Class<?>... parameterTypes) {
+        try {
+            return declared ? clazz.getDeclaredMethod(name, parameterTypes) : clazz.getMethod(name, parameterTypes);
+        } catch (NoSuchMethodException e) {
+            e.printStackTrace();
+        }
+        
+        return null;
+    }
+    
+    public static void setFieldValue(Field field, Object obj, Object value) {
+        try {
+            field.set(obj, value);
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
+    }
+    
+}