diff --git a/kernel/trunk/kernel.asm b/kernel/trunk/kernel.asm
index 3a473a38eb..312f2fa307 100644
--- a/kernel/trunk/kernel.asm
+++ b/kernel/trunk/kernel.asm
@@ -2944,22 +2944,20 @@ nosb8:
 ; edx = [top]*65536 + [bottom]
         mov     eax, [_display.width]
         mov     ebx, [_display.height]
-        dec     eax
-        dec     ebx
 ; check [right]
         cmp     cx, ax
-        ja      .exit
+        jae     .exit
 ; check [left]
         ror     ecx, 16
         cmp     cx, ax
-        ja      .exit
+        jae     .exit
 ; check [bottom]
         cmp     dx, bx
-        ja      .exit
+        jae     .exit
 ; check [top]
         ror     edx, 16
         cmp     dx, bx
-        ja      .exit
+        jae     .exit
 
         movzx   eax, cx  ; [left]
         movzx   ebx, dx  ; [top]
diff --git a/kernel/trunk/video/vesa20.inc b/kernel/trunk/video/vesa20.inc
index 4895b93c96..e6cbecd231 100644
--- a/kernel/trunk/video/vesa20.inc
+++ b/kernel/trunk/video/vesa20.inc
@@ -2147,20 +2147,20 @@ vesa20_drawbackground_stretch:
         mov     eax, [BgrDataWidth]
         dec     eax
         xor     edx, edx
-        div     dword [screen_workarea.right]
+        div     dword [_display.width]
         push    eax     ; high
         xor     eax, eax
-        div     dword [screen_workarea.right]
+        div     dword [_display.width]
         push    eax     ; low
 
 ; the same for height
         mov     eax, [BgrDataHeight]
         dec     eax
         xor     edx, edx
-        div     dword [screen_workarea.bottom]
+        div     dword [_display.height]
         push    eax     ; high
         xor     eax, eax
-        div     dword [screen_workarea.bottom]
+        div     dword [_display.height]
         push    eax     ; low
 
 ; External loop for all y from start to end