diff --git a/reactos/subsys/win32k/dib/dib16bpp.c b/reactos/subsys/win32k/dib/dib16bpp.c
index 060246fb5e5..e6d00fd10d0 100644
--- a/reactos/subsys/win32k/dib/dib16bpp.c
+++ b/reactos/subsys/win32k/dib/dib16bpp.c
@@ -630,11 +630,11 @@ BOOLEAN DIB_16BPP_StretchBlt(SURFOBJ *DestSurf, SURFOBJ *SourceSurf,
      BitsPerFormat(SourceSurf->iBitmapFormat), SourceRect->left, SourceRect->top, SourceRect->right, SourceRect->bottom,
      DestRect->left, DestRect->top, DestRect->right, DestRect->bottom);
 
-    SrcSizeY = SourceRect->bottom;
-    SrcSizeX = SourceRect->right;
+    SrcSizeY = SourceRect->bottom - SourceRect->top;
+    SrcSizeX = SourceRect->right - SourceRect->left;
   
-    DesSizeY = DestRect->bottom;
-    DesSizeX = DestRect->right;   
+    DesSizeY = DestRect->bottom - DestRect->top;
+    DesSizeX = DestRect->right - DestRect->left;   
    
 	zoomX = DesSizeX / SrcSizeX;
     if (zoomX==0) zoomX=1;
diff --git a/reactos/subsys/win32k/dib/dib1bpp.c b/reactos/subsys/win32k/dib/dib1bpp.c
index e782f268413..9bbd125af6d 100644
--- a/reactos/subsys/win32k/dib/dib1bpp.c
+++ b/reactos/subsys/win32k/dib/dib1bpp.c
@@ -518,11 +518,11 @@ BOOLEAN DIB_1BPP_StretchBlt(SURFOBJ *DestSurf, SURFOBJ *SourceSurf,
    int saveY;
    BOOLEAN DesIsBiggerY=FALSE;
 
-   SrcSizeY = SourceRect->bottom;
-   SrcSizeX = SourceRect->right;
-  
-   DesSizeY = DestRect->bottom;
-   DesSizeX = DestRect->right;   
+   SrcSizeY = SourceRect->bottom - SourceRect->top;
+   SrcSizeX = SourceRect->right - SourceRect->left;
+
+   DesSizeY = DestRect->bottom - DestRect->top;
+   DesSizeX = DestRect->right - DestRect->left;
 
    zoomX = DesSizeX / SrcSizeX;
    if (zoomX==0) zoomX=1;
diff --git a/reactos/subsys/win32k/dib/dib24bpp.c b/reactos/subsys/win32k/dib/dib24bpp.c
index 7e1d626393b..5d1fbf54f83 100644
--- a/reactos/subsys/win32k/dib/dib24bpp.c
+++ b/reactos/subsys/win32k/dib/dib24bpp.c
@@ -513,11 +513,11 @@ BOOLEAN DIB_24BPP_StretchBlt(SURFOBJ *DestSurf, SURFOBJ *SourceSurf,
    int saveY;
    BOOLEAN DesIsBiggerY=FALSE;
 
-   SrcSizeY = SourceRect->bottom;
-   SrcSizeX = SourceRect->right;
-  
-   DesSizeY = DestRect->bottom;
-   DesSizeX = DestRect->right;
+   SrcSizeY = SourceRect->bottom - SourceRect->top;
+   SrcSizeX = SourceRect->right - SourceRect->left;
+
+   DesSizeY = DestRect->bottom - DestRect->top;
+   DesSizeX = DestRect->right - DestRect->left;
 
    zoomX = DesSizeX / SrcSizeX;
    if (zoomX==0) zoomX=1;
diff --git a/reactos/subsys/win32k/dib/dib32bpp.c b/reactos/subsys/win32k/dib/dib32bpp.c
index 7a40a3cc647..1302ab480f5 100644
--- a/reactos/subsys/win32k/dib/dib32bpp.c
+++ b/reactos/subsys/win32k/dib/dib32bpp.c
@@ -557,11 +557,11 @@ BOOLEAN DIB_32BPP_StretchBlt(SURFOBJ *DestSurf, SURFOBJ *SourceSurf,
             BitsPerFormat(SourceSurf->iBitmapFormat), SourceRect->left, SourceRect->top, SourceRect->right, 
             SourceRect->bottom, DestRect->left, DestRect->top, DestRect->right, DestRect->bottom);
 
-    SrcSizeY = SourceRect->bottom;
-    SrcSizeX = SourceRect->right;
+    SrcSizeY = SourceRect->bottom - SourceRect->top;
+    SrcSizeX = SourceRect->right - SourceRect->left;
   
-    DesSizeY = DestRect->bottom;
-    DesSizeX = DestRect->right; 
+    DesSizeY = DestRect->bottom - DestRect->top;
+    DesSizeX = DestRect->right - DestRect->left; 
 
     zoomX = DesSizeX / SrcSizeX;
     if (zoomX==0) zoomX=1;
diff --git a/reactos/subsys/win32k/dib/dib4bpp.c b/reactos/subsys/win32k/dib/dib4bpp.c
index caf6e530cc7..8d673c16fcb 100644
--- a/reactos/subsys/win32k/dib/dib4bpp.c
+++ b/reactos/subsys/win32k/dib/dib4bpp.c
@@ -397,12 +397,11 @@ BOOLEAN DIB_4BPP_StretchBlt(SURFOBJ *DestSurf, SURFOBJ *SourceSurf,
    int saveY;
    BOOLEAN DesIsBiggerY=FALSE;
   
+   SrcSizeY = SourceRect->bottom - SourceRect->top;
+   SrcSizeX = SourceRect->right - SourceRect->left;
 
-   SrcSizeY = SourceRect->bottom;
-   SrcSizeX = SourceRect->right;
-  
-   DesSizeY = DestRect->bottom;
-   DesSizeX = DestRect->right; 
+   DesSizeY = DestRect->bottom - DestRect->top;
+   DesSizeX = DestRect->right - DestRect->left;
 
    zoomX = DesSizeX / SrcSizeX;
    if (zoomX==0) zoomX=1;
diff --git a/reactos/subsys/win32k/dib/dib8bpp.c b/reactos/subsys/win32k/dib/dib8bpp.c
index d01b1b597ca..2565227021d 100644
--- a/reactos/subsys/win32k/dib/dib8bpp.c
+++ b/reactos/subsys/win32k/dib/dib8bpp.c
@@ -480,11 +480,11 @@ BOOLEAN DIB_8BPP_StretchBlt(SURFOBJ *DestSurf, SURFOBJ *SourceSurf,
      BitsPerFormat(SourceSurf->iBitmapFormat), SourceRect->left, SourceRect->top, SourceRect->right, SourceRect->bottom,
      DestRect->left, DestRect->top, DestRect->right, DestRect->bottom);
 
-   SrcSizeY = SourceRect->bottom;
-   SrcSizeX = SourceRect->right;
-  
-   DesSizeY = DestRect->bottom;
-   DesSizeX = DestRect->right;
+   SrcSizeY = SourceRect->bottom - SourceRect->top;
+   SrcSizeX = SourceRect->right - SourceRect->left;
+
+   DesSizeY = DestRect->bottom - DestRect->top;
+   DesSizeX = DestRect->right - DestRect->left;
 
    zoomX = DesSizeX / SrcSizeX;
    if (zoomX==0) zoomX=1;