diff --git a/src/kernel/turtle/Turtle.hx b/src/kernel/turtle/Turtle.hx
index 3a97a9c..31ca387 100644
--- a/src/kernel/turtle/Turtle.hx
+++ b/src/kernel/turtle/Turtle.hx
@@ -257,7 +257,7 @@ class Turtle {
 		});
 	}
 
-	public static function getItemDetail(?detailed:Bool = false, ?slot:TurtleSlot):Option<ItemInspect> {
+	public static function getItemDetail(slot:TurtleSlot, ?detailed:Bool = false):Option<ItemInspect> {
 		var r = cc.Turtle.getItemDetail(slot + 1); // FIXME: can take detailed as flag. Has to be fixed upstream
 
 		if (r == null) {
diff --git a/src/kernel/turtle/Types.hx b/src/kernel/turtle/Types.hx
index 928eaea..6029b2d 100644
--- a/src/kernel/turtle/Types.hx
+++ b/src/kernel/turtle/Types.hx
@@ -23,4 +23,7 @@ typedef ItemInspect = {
 	public var count:Int;
 }
 
+/**
+	The slot nummber for turtle inventory. 0 based.
+**/
 typedef TurtleSlot = Int;