diff --git a/mkfs/main.c b/mkfs/main.c
index 9dd618ce..8a4c9523 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -1341,6 +1341,13 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 	    btrfs_bg_type_to_tolerated_failures(data_profile))
 		warning("metadata has lower redundancy than data!\n");
 
+	printf("NOTE: several default settings have changed in version 5.15, please make sure\n");
+	printf("      this does not affect your deployments:\n");
+	printf("      - DUP for metadata (-m dup)\n");
+	printf("      - enabled no-holes (-O no-holes)\n");
+	printf("      - enabled free-space-tree (-R free-space-tree)\n");
+	printf("\n");
+
 	mkfs_cfg.label = label;
 	memcpy(mkfs_cfg.fs_uuid, fs_uuid, sizeof(mkfs_cfg.fs_uuid));
 	mkfs_cfg.num_bytes = dev_block_count;