diff --git a/src/main/java/fr/moribus/imageonmap/guiproko/core/ExplorerGui.java b/src/main/java/fr/moribus/imageonmap/guiproko/core/ExplorerGui.java
index a98344f..a4ea4c8 100644
--- a/src/main/java/fr/moribus/imageonmap/guiproko/core/ExplorerGui.java
+++ b/src/main/java/fr/moribus/imageonmap/guiproko/core/ExplorerGui.java
@@ -79,6 +79,13 @@ abstract public class ExplorerGui<T> extends ActionGui
     
     private Mode mode = Mode.CREATIVE;
 
+
+    public ExplorerGui()
+    {
+        // Defined early to be able to use getSize() in the onUpdate method.
+        setSize(MAX_INVENTORY_SIZE);
+    }
+
     /**
      * Sets the displayed data.
      *
@@ -343,8 +350,6 @@ abstract public class ExplorerGui<T> extends ActionGui
             pageCountY = (int)Math.ceil((double)dataHeight / (double)viewHeight);
         }
         
-        setSize(MAX_INVENTORY_SIZE);
-        
         if(pageCountX > 1)
         {
             action("previous", MAX_INVENTORY_SIZE - INVENTORY_ROW_SIZE);