diff --git a/InvUI/src/main/java/de/studiocode/invui/gui/impl/SimpleTabGUI.java b/InvUI/src/main/java/de/studiocode/invui/gui/impl/SimpleTabGUI.java
index 7d852ee..1602966 100644
--- a/InvUI/src/main/java/de/studiocode/invui/gui/impl/SimpleTabGUI.java
+++ b/InvUI/src/main/java/de/studiocode/invui/gui/impl/SimpleTabGUI.java
@@ -8,6 +8,7 @@ import de.studiocode.invui.gui.structure.Structure;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -38,6 +39,8 @@ public class SimpleTabGUI extends TabGUI {
     }
     
     private List<SlotElement> getLinkingElements(GUI gui) {
+        if (gui == null) return null;
+        
         List<SlotElement> elements = new ArrayList<>();
         for (int slot = 0; slot < gui.getSize(); slot++) {
             SlotElement link = new LinkedSlotElement(gui, slot);
@@ -48,7 +51,7 @@ public class SimpleTabGUI extends TabGUI {
     }
     
     public List<GUI> getTabs() {
-        return tabs;
+        return Collections.unmodifiableList(tabs);
     }
     
     @Override
@@ -56,4 +59,9 @@ public class SimpleTabGUI extends TabGUI {
         return linkingElements.get(tab);
     }
     
+    @Override
+    public boolean isTabAvailable(int tab) {
+        return tabs.get(tab) != null;
+    }
+    
 }
diff --git a/InvUI/src/main/java/de/studiocode/invui/gui/impl/TabGUI.java b/InvUI/src/main/java/de/studiocode/invui/gui/impl/TabGUI.java
index b6668c9..808c124 100644
--- a/InvUI/src/main/java/de/studiocode/invui/gui/impl/TabGUI.java
+++ b/InvUI/src/main/java/de/studiocode/invui/gui/impl/TabGUI.java
@@ -12,7 +12,7 @@ public abstract class TabGUI extends BaseGUI implements Controllable {
     private final int tabAmount;
     private final int[] listSlots;
     
-    private int currentTab;
+    private int currentTab = -1;
     
     public TabGUI(int width, int height, int tabAmount, int... listSlots) {
         super(width, height);
@@ -28,12 +28,16 @@ public abstract class TabGUI extends BaseGUI implements Controllable {
     public void showTab(int tab) {
         if (tab < 0 || tab >= tabAmount)
             throw new IllegalArgumentException("Tab out of bounds");
+        if (!isTabAvailable(tab))
+            return;
         
         currentTab = tab;
         update();
     }
     
     protected void update() {
+        if (currentTab == -1) currentTab = getFirstAvailableTab();
+        
         updateControlItems();
         updateContent();
     }
@@ -47,10 +51,20 @@ public abstract class TabGUI extends BaseGUI implements Controllable {
         }
     }
     
+    public int getFirstAvailableTab() {
+        for (int tab = 0; tab < tabAmount; tab++) {
+            if (isTabAvailable(tab)) return tab;
+        }
+        
+        throw new UnsupportedOperationException("At least one tab needs to be available");
+    }
+    
     public int getCurrentTab() {
         return currentTab;
     }
     
     public abstract List<SlotElement> getSlotElements(int tab);
     
+    public abstract boolean isTabAvailable(int tab);
+    
 }