diff --git a/src/main/java/galaxyoyo/unknown/api/editor/sprites/SpriteRegister.java b/src/main/java/galaxyoyo/unknown/api/editor/sprites/SpriteRegister.java
index f8c0e52..206e5f9 100644
--- a/src/main/java/galaxyoyo/unknown/api/editor/sprites/SpriteRegister.java
+++ b/src/main/java/galaxyoyo/unknown/api/editor/sprites/SpriteRegister.java
@@ -1,5 +1,7 @@
 package galaxyoyo.unknown.api.editor.sprites;
 
+import galaxyoyo.unknown.client.main.Main;
+
 import java.awt.image.BufferedImage;
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;
@@ -8,12 +10,16 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.URISyntaxException;
+import java.net.URLDecoder;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.ArrayList;
+import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
 
 import javax.imageio.ImageIO;
 
@@ -26,16 +32,39 @@ public class SpriteRegister
 	private static Map<String, List<List<Double>>> nameToCoords;
 	private static Map<String, Category> sprites = new HashMap<String, Category>();
 	
-	public static void unpack()
+	public static void unpack() throws IOException, URISyntaxException
 	{
-		try
+		if (Main.isInDevelopmentMode())
 		{
 			File dir = new File(SpriteRegister.class.getResource("/assets").toURI());
 			unpackDir(dir);
 		}
-		catch (URISyntaxException | IOException e)
+		else
 		{
-			e.printStackTrace();
+			@SuppressWarnings("deprecation")
+			String path = URLDecoder.decode(SpriteRegister.class.getProtectionDomain().getCodeSource().getLocation().getPath());
+			path = path.substring(1, path.length());
+			File jarFile = new File(path);
+
+			if(jarFile.isFile())
+			{
+				JarFile jar = new JarFile(jarFile);
+				Enumeration<JarEntry> entries = jar.entries();
+				while (entries.hasMoreElements())
+				{
+					JarEntry je = entries.nextElement();
+					String name = je.getName();
+					if (name.startsWith("assets/"))
+					{
+						File f = new File(name);
+						if (name.endsWith("/"))
+							f.mkdirs();
+						else if (!f.isFile())
+							Files.copy(jar.getInputStream(je), Paths.get(f.toURI()));
+					}
+				}
+				jar.close();
+			}
 		}
 	}
 	
diff --git a/src/main/java/galaxyoyo/unknown/client/main/Main.java b/src/main/java/galaxyoyo/unknown/client/main/Main.java
index 73ab639..bbde9ff 100644
--- a/src/main/java/galaxyoyo/unknown/client/main/Main.java
+++ b/src/main/java/galaxyoyo/unknown/client/main/Main.java
@@ -14,6 +14,7 @@ import java.awt.Graphics2D;
 import java.awt.GraphicsEnvironment;
 import java.awt.HeadlessException;
 import java.awt.image.BufferedImage;
+import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.net.URL;
@@ -66,7 +67,15 @@ public class Main
 		
 		Locale.setDefault(Locale.FRANCE);
 		
-		DEV = Main.class.getClassLoader().getResource("/META-INF/MANIFEST.MF") == null;
+		try
+		{
+			new File(Main.class.getResource("/assets").toURI());
+			DEV = true;
+		}
+		catch (Throwable t)
+		{
+			DEV = false;
+		}
 		
 		Logger LOGGER = (Logger) LogManager.getRootLogger();
 		ConsoleAppender console = ConsoleAppender.newBuilder().setLayout(PatternLayout.newBuilder().withPattern("[%d{dd/MM/yyyy}] [%d{HH:mm:ss}] [%t] [%c] [%p] %m%n").build()).setName("Console").build();
@@ -110,7 +119,14 @@ public class Main
 			}
 		}
 		
-		SpriteRegister.unpack();
+		try
+		{
+			SpriteRegister.unpack();
+		}
+		catch (IOException | URISyntaxException e)
+		{
+			e.printStackTrace();
+		}
 		
 		SpriteRegister.refreshAllSprites();