diff --git a/shared-core/mga_state.c b/shared-core/mga_state.c
index 7d1df09a..558beed1 100644
--- a/shared-core/mga_state.c
+++ b/shared-core/mga_state.c
@@ -60,9 +60,9 @@ static void mga_emit_clip_rect(drm_mga_private_t * dev_priv,
 			  MGA_LEN + MGA_EXEC, 0x80000000);
 	}
 	DMA_BLOCK(MGA_DMAPAD, 0x00000000,
-		  MGA_CXBNDRY, (box->x2 << 16) | box->x1,
+		  MGA_CXBNDRY, ((box->x2 - 1) << 16) | box->x1,
 		  MGA_YTOP, box->y1 * pitch,
-		  MGA_YBOT, box->y2 * pitch);
+		  MGA_YBOT, (box->y2 - 1) * pitch);
 
 	ADVANCE_DMA();
 }
diff --git a/shared/mga_state.c b/shared/mga_state.c
index 43659825..3dc1999a 100644
--- a/shared/mga_state.c
+++ b/shared/mga_state.c
@@ -62,9 +62,9 @@ static void mga_emit_clip_rect( drm_mga_private_t *dev_priv,
 			   MGA_LEN + MGA_EXEC,	0x80000000 );
 	}
 	DMA_BLOCK( MGA_DMAPAD,	0x00000000,
-		   MGA_CXBNDRY,	(box->x2 << 16) | box->x1,
+		   MGA_CXBNDRY,	((box->x2 - 1) << 16) | box->x1,
 		   MGA_YTOP,	box->y1 * pitch,
-		   MGA_YBOT,	box->y2 * pitch );
+		   MGA_YBOT,	(box->y2 - 1) * pitch );
 
 	ADVANCE_DMA();
 }