diff --git a/InvUI/src/main/java/de/studiocode/invui/InvUI.java b/InvUI/src/main/java/de/studiocode/invui/InvUI.java
index 21b18f1..1b7c50a 100644
--- a/InvUI/src/main/java/de/studiocode/invui/InvUI.java
+++ b/InvUI/src/main/java/de/studiocode/invui/InvUI.java
@@ -6,6 +6,7 @@ import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.server.PluginDisableEvent;
 import org.bukkit.plugin.Plugin;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -17,27 +18,40 @@ public class InvUI implements Listener {
     private static InvUI instance;
     
     private final List<Runnable> disableHandlers = new ArrayList<>();
-    private final Plugin plugin;
+    private Plugin plugin;
     
     private InvUI() {
-        plugin = ReflectionUtils.getFieldValue(PLUGIN_CLASS_LOADER_PLUGIN_FIELD, getClass().getClassLoader());
-        Bukkit.getPluginManager().registerEvents(this, plugin);
     }
     
     public static InvUI getInstance() {
         return instance == null ? instance = new InvUI() : instance;
     }
     
+    @NotNull
     public Plugin getPlugin() {
+        if (plugin == null) {
+            // get plugin from class loader if it wasn't set manually
+            plugin = ReflectionUtils.getFieldValue(PLUGIN_CLASS_LOADER_PLUGIN_FIELD, getClass().getClassLoader());
+            Bukkit.getPluginManager().registerEvents(this, plugin);
+        }
+        
         return plugin;
     }
     
-    public void addDisableHandler(Runnable runnable) {
+    public void setPlugin(@NotNull Plugin plugin) {
+        if (this.plugin != null)
+            throw new IllegalStateException("Plugin is already set");
+        
+        Bukkit.getPluginManager().registerEvents(this, plugin);
+        this.plugin = plugin;
+    }
+    
+    public void addDisableHandler(@NotNull Runnable runnable) {
         disableHandlers.add(runnable);
     }
     
     @EventHandler
-    public void handlePluginDisable(PluginDisableEvent event) {
+    private void handlePluginDisable(PluginDisableEvent event) {
         if (event.getPlugin().equals(plugin)) {
             disableHandlers.forEach(Runnable::run);
         }