diff --git a/file.c b/file.c
index 4920f50..d983518 100644
--- a/file.c
+++ b/file.c
@@ -247,7 +247,7 @@ rpc_file_read(struct ubus_context *ctx, struct ubus_object *obj,
 		}
 	}
 
-	*(wbuf + len) = 0;
+	*(wbuf + len) = '\0';
 	blobmsg_add_string_buffer(&buf);
 
 	ubus_send_reply(ctx, req, buf.head);