diff --git a/src/main/java/com/songoda/ultimatekits/conversion/hooks/DefaultHook.java b/src/main/java/com/songoda/ultimatekits/conversion/hooks/DefaultHook.java
index ca3ca34..5c83620 100644
--- a/src/main/java/com/songoda/ultimatekits/conversion/hooks/DefaultHook.java
+++ b/src/main/java/com/songoda/ultimatekits/conversion/hooks/DefaultHook.java
@@ -1,7 +1,6 @@
 package com.songoda.ultimatekits.conversion.hooks;
 
 import com.songoda.core.compatibility.ServerVersion;
-import com.songoda.ultimatekits.UltimateKits;
 import com.songoda.ultimatekits.conversion.Hook;
 import com.songoda.ultimatekits.utils.ItemSerializer;
 import org.bukkit.inventory.ItemStack;
@@ -10,7 +9,6 @@ import java.util.HashSet;
 import java.util.Set;
 
 public class DefaultHook implements Hook {
-
     public Set<ItemStack> getItems(String kitName) {
         Set<ItemStack> items = new HashSet<>();
 
diff --git a/src/main/java/com/songoda/ultimatekits/utils/ItemSerializer.java b/src/main/java/com/songoda/ultimatekits/utils/ItemSerializer.java
index 9169e55..306c931 100644
--- a/src/main/java/com/songoda/ultimatekits/utils/ItemSerializer.java
+++ b/src/main/java/com/songoda/ultimatekits/utils/ItemSerializer.java
@@ -1,22 +1,17 @@
 package com.songoda.ultimatekits.utils;
 
 import com.songoda.core.compatibility.ClassMapping;
+import com.songoda.core.compatibility.MethodMapping;
 import com.songoda.core.compatibility.ServerVersion;
-import org.bukkit.Bukkit;
 import org.bukkit.inventory.ItemStack;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 
 public class ItemSerializer {
-
     // classes needed for reflections
 
-    private static Class<?> classMojangsonParser;
-    private static Class<?> classItemStack;
-    private static Class<?> classCraftItemStack;
     private static Class<?> classNBTTagCompound;
-    private static Class<?> classBukkitItemStack;
 
     private static Constructor<?> constructorItemStack;
 
@@ -28,82 +23,63 @@ public class ItemSerializer {
     private static Method methodTobItemStack;
     private static Method methodTocItemStack;
     private static Method methodSaveTagToStack;
-    private static Method methodToString;
 
-    /**
-     * Initializes all reflection methods
-     *
-     * @throws NoSuchMethodException
-     * @throws SecurityException
-     * @throws ClassNotFoundException
-     */
-    static  {
+    static {
         try {
-            classMojangsonParser = Class.forName(ServerVersion.isServerVersionAtLeast(ServerVersion.V1_17)
-                    ? "net.minecraft.nbt.MojangsonParser" : formatNMS("net.minecraft.server.NMS.MojangsonParser"));
-            classItemStack = ClassMapping.ITEM_STACK.getClazz();
-            classCraftItemStack = Class.forName(formatNMS("org.bukkit.craftbukkit.NMS.inventory.CraftItemStack"));
+            Class<?> classItemStack = ClassMapping.ITEM_STACK.getClazz();
             classNBTTagCompound = ClassMapping.NBT_TAG_COMPOUND.getClazz();
-            classBukkitItemStack = Class.forName("org.bukkit.inventory.ItemStack");
-            methodParseString = classMojangsonParser.getMethod("parse", String.class);
 
-            if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13))
+            methodParseString = MethodMapping.MOJANGSON_PARSER__PARSE.getMethod(ClassMapping.MOJANGSON_PARSER.getClazz());
+
+            if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13)) {
                 methodToItemStack = classItemStack.getMethod("a", classNBTTagCompound);
-            else if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_11))
+            } else if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_11)) {
                 constructorItemStack = classItemStack.getConstructor(classNBTTagCompound);
-            else
+            } else {
                 methodCreateStack = classItemStack.getMethod("createStack", classNBTTagCompound);
-            methodTobItemStack = classCraftItemStack.getMethod("asBukkitCopy", classItemStack);
+            }
+            methodTobItemStack = ClassMapping.CRAFT_ITEM_STACK.getClazz().getMethod("asBukkitCopy", classItemStack);
 
-            methodTocItemStack = classCraftItemStack.getDeclaredMethod("asNMSCopy", classBukkitItemStack);
-            methodSaveTagToStack = classItemStack.getMethod("save", classNBTTagCompound);
-            methodToString = classNBTTagCompound.getMethod("toString");
-        } catch (NoSuchMethodException | ClassNotFoundException e) {
-            e.getStackTrace();
+            methodTocItemStack = MethodMapping.CB_ITEM_STACK__AS_NMS_COPY.getMethod(ClassMapping.CRAFT_ITEM_STACK.getClazz());
+            methodSaveTagToStack = MethodMapping.ITEM_STACK__SAVE.getMethod(ClassMapping.ITEM_STACK.getClazz());
+        } catch (NoSuchMethodException ex) {
+            ex.getStackTrace();
         }
     }
 
-    /**
-     * Inserts the version declaration for any string containing NMS
-     *
-     * @param s the string to format, must contain NMS.
-     * @return formatted string
-     */
-    private static String formatNMS(String s) {
-        String packageName = Bukkit.getServer().getClass().getPackage().getName();
-        String nmsVersion = packageName.substring(packageName.lastIndexOf('.') + 1);
-        return s.replace("NMS", nmsVersion);
-    }
-
     /**
      * Deserializes a JSON String
      *
      * @param jsonString the JSON String to parse
+     *
      * @return the deserialized ItemStack
      */
     public static ItemStack deserializeItemStackFromJson(String jsonString) {
         try {
             Object nbtTagCompound = methodParseString.invoke(null, jsonString);
-            Object citemStack;
+            Object cItemStack;
 
-            if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13))
-                citemStack = methodToItemStack.invoke(null, nbtTagCompound);
-            else if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_11))
-                citemStack = constructorItemStack.newInstance(nbtTagCompound);
-            else
-                citemStack = methodCreateStack.invoke(null, nbtTagCompound);
+            if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13)) {
+                cItemStack = methodToItemStack.invoke(null, nbtTagCompound);
+            } else if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_11)) {
+                cItemStack = constructorItemStack.newInstance(nbtTagCompound);
+            } else {
+                cItemStack = methodCreateStack.invoke(null, nbtTagCompound);
+            }
 
-            return (ItemStack) methodTobItemStack.invoke(null, citemStack);
+            return (ItemStack) methodTobItemStack.invoke(null, cItemStack);
         } catch (Exception ex) {
             ex.printStackTrace();
-            return null;
         }
+
+        return null;
     }
 
     /**
      * Serializes an item stack
      *
      * @param itemStack the ItemStack to parse
+     *
      * @return condensed JSON String
      */
     public static String serializeItemStackToJson(ItemStack itemStack) {
@@ -113,10 +89,11 @@ public class ItemSerializer {
 
             methodSaveTagToStack.invoke(citemStack, nbtTagCompoundObject);
 
-            return (String) methodToString.invoke(nbtTagCompoundObject);
-        } catch (Exception e) {
-            e.printStackTrace();
-            return null;
+            return nbtTagCompoundObject.toString();
+        } catch (Exception ex) {
+            ex.printStackTrace();
         }
+
+        return null;
     }
-}
\ No newline at end of file
+}