diff --git a/lib/intel_chipset.h b/lib/intel_chipset.h
index 35edaf77..668bf598 100755
--- a/lib/intel_chipset.h
+++ b/lib/intel_chipset.h
@@ -114,7 +114,9 @@
 #define IS_945(devid)		(devid == PCI_CHIP_I945_G || \
 				 devid == PCI_CHIP_I945_GM || \
 				 devid == PCI_CHIP_I945_GME || \
-				 devid == PCI_CHIP_G33_G || \
+				 IS_G33(devid))
+
+#define IS_G33(devid)		(devid == PCI_CHIP_G33_G || \
 				 devid == PCI_CHIP_Q33_G || \
 				 devid == PCI_CHIP_Q35_G || IS_IGD(devid))
 
diff --git a/tests/gem_partial_pwrite_pread.c b/tests/gem_partial_pwrite_pread.c
index 57076cff..e00167fc 100644
--- a/tests/gem_partial_pwrite_pread.c
+++ b/tests/gem_partial_pwrite_pread.c
@@ -124,7 +124,8 @@ blt_bo_fill(drm_intel_bo *tmp_bo, drm_intel_bo *bo, int val)
 
 	drm_intel_gem_bo_unmap_gtt(tmp_bo);
 
-	if (bo->offset < num_trash_bos*1024*1024)
+	if (bo->offset < num_trash_bos*1024*1024 &&
+	    (IS_G33(devid) || intel_gen(devid) >= 4))
 		trash_aperture();
 
 	copy_bo(tmp_bo, bo);