diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index be18ccd..6780b2e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5214,7 +5214,7 @@
 	start = (void *)PAGE_ALIGN((unsigned long)start);
 	end = (void *)((unsigned long)end & PAGE_MASK);
 	for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
-		if (poison)
+		if ((unsigned int)poison <= 0xFF)
 			memset(pos, poison, PAGE_SIZE);
 		free_reserved_page(virt_to_page(pos));
 	}