diff --git a/builtin/repack.c b/builtin/repack.c
index b85483a148..36d1f03671 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -22,6 +22,8 @@
 #define LOOSEN_UNREACHABLE 2
 #define PACK_CRUFT 4
 
+#define DELETE_PACK 1
+
 static int pack_everything;
 static int delta_base_offset = 1;
 static int pack_kept_objects = -1;
@@ -564,7 +566,7 @@ static void midx_included_packs(struct string_list *include,
 		}
 	} else {
 		for_each_string_list_item(item, existing_nonkept_packs) {
-			if (item->util)
+			if ((uintptr_t)item->util & DELETE_PACK)
 				continue;
 			string_list_insert(include, xstrfmt("%s.idx", item->string));
 		}
@@ -1002,7 +1004,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 			 * was given) and that we will actually delete this pack
 			 * (if `-d` was given).
 			 */
-			item->util = (void*)(intptr_t)!string_list_has_string(&names, sha1);
+			if (!string_list_has_string(&names, sha1))
+				item->util = (void*)(uintptr_t)((size_t)item->util | DELETE_PACK);
 		}
 	}
 
@@ -1026,7 +1029,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (delete_redundant) {
 		int opts = 0;
 		for_each_string_list_item(item, &existing_nonkept_packs) {
-			if (!item->util)
+			if (!((uintptr_t)item->util & DELETE_PACK))
 				continue;
 			remove_redundant_pack(packdir, item->string);
 		}