diff --git a/src/sys/graphics/objgfx30.cpp b/src/sys/graphics/objgfx30.cpp
index 8d5f7a5..503176b 100755
--- a/src/sys/graphics/objgfx30.cpp
+++ b/src/sys/graphics/objgfx30.cpp
@@ -56,7 +56,7 @@
   if (!pal) return FALSE;
   memset(pal,0,sizeof(TRGB)*256);
   MaxX=_xRes-1;
-  xRes=_xRes;
+  xRes=_xRes*((BPP+7) >> 3);
   MaxY=_yRes-1;
   yRes=_yRes;
   LineOfs[0]=0;