diff --git a/HMCLAPI/src/main/java/org/jackhuang/hmcl/api/game/IMinecraftLibrary.java b/HMCLAPI/src/main/java/org/jackhuang/hmcl/api/game/IMinecraftLibrary.java
index 6f5d8e00c..3156c4bcf 100644
--- a/HMCLAPI/src/main/java/org/jackhuang/hmcl/api/game/IMinecraftLibrary.java
+++ b/HMCLAPI/src/main/java/org/jackhuang/hmcl/api/game/IMinecraftLibrary.java
@@ -37,8 +37,8 @@ public interface IMinecraftLibrary extends Cloneable {
     File getFilePath(File gameDir);
 
     String getName();
-
-    boolean isRequiredToUnzip();
+    
+    boolean isNative();
     
     String getDownloadURL(String downloadSource);
     
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/launch/MinecraftLoader.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/launch/MinecraftLoader.java
index c78127dec..f82889ce9 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/launch/MinecraftLoader.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/launch/MinecraftLoader.java
@@ -46,7 +46,7 @@ public class MinecraftLoader extends AbstractMinecraftLoader {
         StringBuilder library = new StringBuilder("");
         ArrayList<MinecraftLibrary> opt = new ArrayList<>();
         for (MinecraftLibrary l : version.libraries)
-            if (l.allow() && !l.isRequiredToUnzip()) {
+            if (l.allow() && !l.isNative()) {
                 if (l.getName().toLowerCase(Locale.US).contains("optifine")) {
                     opt.add(l);
                     continue;
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/AbstractMinecraftLibrary.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/AbstractMinecraftLibrary.java
index 66c204e4a..ce68b277f 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/AbstractMinecraftLibrary.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/AbstractMinecraftLibrary.java
@@ -26,7 +26,7 @@ import org.jackhuang.hmcl.api.game.IMinecraftLibrary;
  */
 public abstract class AbstractMinecraftLibrary implements IMinecraftLibrary {
 
-    private String name;
+    private final String name;
 
     public AbstractMinecraftLibrary(String name) {
         this.name = name;
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftLibrary.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftLibrary.java
index 2c89981f1..06e17f28e 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftLibrary.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftLibrary.java
@@ -84,7 +84,7 @@ public class MinecraftLibrary extends AbstractMinecraftLibrary {
     }
 
     @Override
-    public boolean isRequiredToUnzip() {
+    public boolean isNative() {
         return natives != null && allow();
     }
 
@@ -125,11 +125,7 @@ public class MinecraftLibrary extends AbstractMinecraftLibrary {
                 downloads.classifiers = new HashMap<>();
             if (!downloads.classifiers.containsKey(getNative()))
                 downloads.classifiers.put(getNative(), info = new LibraryDownloadInfo());
-            else {
-                info = downloads.classifiers.get(getNative());
-                if (info == null)
-                    info = new LibraryDownloadInfo();
-            }
+            else info = downloads.classifiers.get(getNative());
         } else {
             if (downloads.artifact == null)
                 downloads.artifact = new LibraryDownloadInfo();
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftOldLibrary.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftOldLibrary.java
index 85636ca8a..56e6a1550 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftOldLibrary.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftOldLibrary.java
@@ -30,7 +30,7 @@ public class MinecraftOldLibrary extends MinecraftLibrary {
     }
 
     @Override
-    public boolean isRequiredToUnzip() {
+    public boolean isNative() {
         return false;
     }
 
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersion.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersion.java
index 5bd23d43a..438746ddf 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersion.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersion.java
@@ -21,8 +21,10 @@ import org.jackhuang.hmcl.api.game.IMinecraftLibrary;
 import com.google.gson.annotations.SerializedName;
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -164,8 +166,7 @@ public class MinecraftVersion implements Cloneable, Comparable<MinecraftVersion>
     }
 
     public File getNatives(File gameDir) {
-        return new File(gameDir, "versions/" + id + "/" + id
-                                 + "-natives");
+        return new File(gameDir, "versions/" + id + "/" + id + "-natives");
     }
 
     public boolean isAllowedToUnpackNatives() {
@@ -193,8 +194,6 @@ public class MinecraftVersion implements Cloneable, Comparable<MinecraftVersion>
         return Objects.equals(this.id, ((MinecraftVersion) obj).id);
     }
     
-    
-
     public AssetIndexDownloadInfo getAssetsIndex() {
         if (assetIndex == null)
             assetIndex = new AssetIndexDownloadInfo(assets == null ? AssetsIndex.DEFAULT_ASSET_NAME : assets);
@@ -212,7 +211,7 @@ public class MinecraftVersion implements Cloneable, Comparable<MinecraftVersion>
         return i;
     }
 
-    public Set<IMinecraftLibrary> getLibraries() {
-        return libraries == null ? new HashSet<>() : new HashSet<>(libraries);
+    public List<IMinecraftLibrary> getLibraries() {
+        return libraries == null ? new LinkedList<>() : Collections.unmodifiableList(libraries);
     }
 }
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersionManager.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersionManager.java
index f2f4493ca..589a51cc8 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersionManager.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/core/version/MinecraftVersionManager.java
@@ -248,7 +248,7 @@ public class MinecraftVersionManager<T extends IMinecraftService> extends IMinec
         ArrayList<File> unzippings = new ArrayList<>();
         ArrayList<Extract> extractRules = new ArrayList<>();
         for (IMinecraftLibrary l : v.libraries)
-            if (l.isRequiredToUnzip() && v.isAllowedToUnpackNatives()) {
+            if (l.isNative() && v.isAllowedToUnpackNatives()) {
                 unzippings.add(getLibraryFile(v, l));
                 extractRules.add(l.getDecompressExtractRules());
             }