diff --git a/src/forisUrls.js b/src/forisUrls.js
index a5f83ba..3499d27 100644
--- a/src/forisUrls.js
+++ b/src/forisUrls.js
@@ -1,3 +1,10 @@
+/*
+ * Copyright (C) 2019 CZ.NIC z.s.p.o. (http://www.nic.cz/)
+ *
+ * This is free software, licensed under the GNU General Public License v3.
+ * See /LICENSE for more information.
+ */
+
 export const REFORIS_URL_PREFIX = process.env.LIGHTTPD ? "/reforis" : "";
 
 export const ForisURLs = {
diff --git a/src/index.js b/src/index.js
index 267ba1f..935eb58 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,3 +1,10 @@
+/*
+ * Copyright (C) 2019 CZ.NIC z.s.p.o. (http://www.nic.cz/)
+ *
+ * This is free software, licensed under the GNU General Public License v3.
+ * See /LICENSE for more information.
+ */
+
 // API
 export { useAPIGet } from "api/get";
 export { useAPIPost } from "api/post";
diff --git a/src/utils/objectHelpers.js b/src/utils/objectHelpers.js
index 28e3672..9fe5b8e 100644
--- a/src/utils/objectHelpers.js
+++ b/src/utils/objectHelpers.js
@@ -1,3 +1,10 @@
+/*
+ * Copyright (C) 2019 CZ.NIC z.s.p.o. (http://www.nic.cz/)
+ *
+ * This is free software, licensed under the GNU General Public License v3.
+ * See /LICENSE for more information.
+ */
+
 /** Return undefined if object has no keys, otherwise return object. */
 export function undefinedIfEmpty(instance) {
     if (Object.keys(instance).length > 0) {