1 files changed, 9 insertions, 8 deletions

diff --git a/spec/fltk-images-bitmaps.ads b/spec/fltk-images-bitmaps.ads
index 73afc62..9577273 100644
--- a/spec/fltk-images-bitmaps.ads
+++ b/spec/fltk-images-bitmaps.ads
@@ -33,7 +33,8 @@ package FLTK.Images.Bitmaps is
                (Data          : in Color_Component_Array;
                 Width, Height : in Natural)
             return Bitmap
-        with Pre => Data'Length >= Bytes_Needed (Width) * Height;
+        with Pre =>
+            Data'Length >= Size_Type (Bytes_Needed (Width)) * Size_Type (Height);
 
     end Forge;
 
@@ -66,31 +67,31 @@ package FLTK.Images.Bitmaps is
 
     function Data_Size
            (This : in Bitmap)
-        return Natural;
+        return Size_Type;
 
     function Get_Datum
            (This  : in Bitmap;
-            Place : in Positive)
+            Place : in Positive_Size)
         return Color_Component
     with Pre => Place <= This.Data_Size;
 
     procedure Set_Datum
            (This  : in out Bitmap;
-            Place : in     Positive;
+            Place : in     Positive_Size;
             Value : in     Color_Component)
     with Pre => Place <= This.Data_Size;
 
     function Slice
            (This : in Bitmap;
-            Low  : in Positive;
-            High : in Natural)
+            Low  : in Positive_Size;
+            High : in Size_Type)
         return Color_Component_Array
     with Pre => High <= This.Data_Size,
-        Post => Slice'Result'Length = Integer'Max (0, High - Low + 1);
+        Post => Slice'Result'Length = Size_Type'Max (0, High - Low + 1);
 
     procedure Overwrite
            (This   : in out Bitmap;
-            Place  : in     Positive;
+            Place  : in     Positive_Size;
             Values : in     Color_Component_Array)
     with Pre => Place + Values'Length - 1 <= This.Data_Size;