diff --git a/src/video/vid_nv_riva128.c b/src/video/vid_nv_riva128.c
index 788dcfab5..59c16e3aa 100644
--- a/src/video/vid_nv_riva128.c
+++ b/src/video/vid_nv_riva128.c
@@ -2771,7 +2771,7 @@ void riva128_ptimer_tick(void *p)
 			}
 			if (linear_addr)
 			{
-				mem_mapping_set_addr(&riva128->linear_mapping, linear_addr, 0xc00000);
+				mem_mapping_set_addr(&riva128->linear_mapping, linear_addr, 0x1000000);
 				mem_mapping_set_addr(&riva128->ramin_mapping, linear_addr + 0xc00000, 0x200000);
 			}
 		}
diff --git a/src/video/vid_svga.c b/src/video/vid_svga.c
index 2fca45358..da148849a 100644
--- a/src/video/vid_svga.c
+++ b/src/video/vid_svga.c
@@ -796,7 +796,7 @@ svga_init(svga_t *svga, void *p, int memsize,
     svga->vram_max = memsize;
     svga->vram_display_mask = svga->vram_mask = memsize - 1;
     svga->decode_mask = 0x7fffff;
-    svga->changedvram = malloc(0x800000 >> 12);
+    svga->changedvram = malloc(memsize >> 12);
     svga->recalctimings_ex = recalctimings_ex;
     svga->video_in  = video_in;
     svga->video_out = video_out;