diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
index 608a2bb..5de69ac 100644
--- a/fs/squashfs/sqfs.c
+++ b/fs/squashfs/sqfs.c
@@ -49,6 +49,7 @@
 
 	if (sqfs_disk_read(0, 1, *sblk) != 1) {
 		free(*sblk);
+		sblk = NULL;
 		return -EINVAL;
 	}
 
@@ -1689,9 +1690,10 @@
 
 void sqfs_close(void)
 {
+	sqfs_decompressor_cleanup(&ctxt);
 	free(ctxt.sblk);
+	ctxt.sblk = NULL;
 	ctxt.cur_dev = NULL;
-	sqfs_decompressor_cleanup(&ctxt);
 }
 
 void sqfs_closedir(struct fs_dir_stream *dirs)