diff --git a/gc.c b/gc.c
index 4d92ede42a..c42d907df5 100644
--- a/gc.c
+++ b/gc.c
@@ -7570,14 +7570,18 @@ typedef int page_compare_func_t(const void *, const void *, void *);
 static struct heap_page **
 allocate_page_list(rb_objspace_t *objspace, page_compare_func_t *comparator)
 {
-    size_t n = heap_eden->total_pages;
-    struct heap_page *page, **page_list = calloc(n, sizeof(struct heap_page *));
+    size_t total_pages = heap_eden->total_pages;
+    struct heap_page *page, **page_list = malloc(total_pages * sizeof(struct heap_page *));
     int i = 0;
 
     list_for_each(&heap_eden->pages, page, page_node) {
         page_list[i++] = page;
+        GC_ASSERT(page != NULL);
     }
-    ruby_qsort(page_list, n, sizeof(struct heap_page *), comparator, NULL);
+    GC_ASSERT(total_pages > 0);
+    GC_ASSERT((size_t)i == total_pages);
+
+    ruby_qsort(page_list, total_pages, sizeof(struct heap_page *), comparator, NULL);
 
     return page_list;
 }