diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3742214..5abc8cf 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5987,8 +5987,15 @@
 
 void free_contig_range(unsigned long pfn, unsigned nr_pages)
 {
-	for (; nr_pages--; ++pfn)
-		__free_page(pfn_to_page(pfn));
+	unsigned int count = 0;
+
+	for (; nr_pages--; pfn++) {
+		struct page *page = pfn_to_page(pfn);
+
+		count += page_count(page) != 1;
+		__free_page(page);
+	}
+	WARN(count != 0, "%d pages are still in use!\n", count);
 }
 #endif