diff --git a/reactos/subsystems/win32/win32k/dib/dib24bpp.c b/reactos/subsystems/win32/win32k/dib/dib24bpp.c
index 24fda4a40f5..d3c60d43236 100644
--- a/reactos/subsystems/win32/win32k/dib/dib24bpp.c
+++ b/reactos/subsystems/win32/win32k/dib/dib24bpp.c
@@ -258,7 +258,7 @@ DIB_24BPP_BitBlt(PBLTINFO BltInfo)
    {
       if (BltInfo->PatternSurface)
       {
-         PatternY = (BltInfo->DestRect.top + BltInfo->BrushOrigin.y) %
+         PatternY = (BltInfo->DestRect.top - BltInfo->BrushOrigin.y) %
                     BltInfo->PatternSurface->sizlBitmap.cy;
       }
       else
@@ -281,8 +281,8 @@ DIB_24BPP_BitBlt(PBLTINFO BltInfo)
          }
 
          if (BltInfo->PatternSurface)
-	 {
-            Pattern = DIB_GetSource(BltInfo->PatternSurface, (DestX + BltInfo->BrushOrigin.x) % BltInfo->PatternSurface->sizlBitmap.cx, PatternY, BltInfo->XlatePatternToDest);
+         {
+            Pattern = DIB_GetSource(BltInfo->PatternSurface, (DestX - BltInfo->BrushOrigin.x) % BltInfo->PatternSurface->sizlBitmap.cx, PatternY, BltInfo->XlatePatternToDest);
          }
 
          Dest = DIB_DoRop(BltInfo->Rop4, Dest, Source, Pattern) & 0xFFFFFF;