diff --git a/src/config.rs b/src/config.rs
index 1d2e6a6..db5398e 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,3 +1,22 @@
+/********************************************************************************
+ *   Prometheus exporter for monitoring network connectivity using icmp pings   *
+ *                                                                              *
+ *   Copyright (C) 2019-2020 Jan Christian Grünhage                             *
+ *   Copyright (C) 2020 Famedly GmbH                                            *
+ *                                                                              *
+ *   This program is free software: you can redistribute it and/or modify       *
+ *   it under the terms of the GNU Affero General Public License as             *
+ *   published by the Free Software Foundation, either version 3 of the         *
+ *   License, or (at your option) any later version.                            *
+ *                                                                              *
+ *   This program is distributed in the hope that it will be useful,            *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of             *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the               *
+ *   GNU Affero General Public License for more details.                        *
+ *                                                                              *
+ *   You should have received a copy of the GNU Affero General Public License   *
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.     *
+ ********************************************************************************/
 use clap::{clap_app, crate_authors, crate_description, crate_name, crate_version};
 use log::info;
 use serde::{Deserialize, Serialize};
diff --git a/src/main.rs b/src/main.rs
index 7083687..ccfffa3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,22 @@
+/********************************************************************************
+ *   Prometheus exporter for monitoring network connectivity using icmp pings   *
+ *                                                                              *
+ *   Copyright (C) 2019-2020 Jan Christian Grünhage                             *
+ *   Copyright (C) 2020 Famedly GmbH                                            *
+ *                                                                              *
+ *   This program is free software: you can redistribute it and/or modify       *
+ *   it under the terms of the GNU Affero General Public License as             *
+ *   published by the Free Software Foundation, either version 3 of the         *
+ *   License, or (at your option) any later version.                            *
+ *                                                                              *
+ *   This program is distributed in the hope that it will be useful,            *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of             *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the               *
+ *   GNU Affero General Public License for more details.                        *
+ *                                                                              *
+ *   You should have received a copy of the GNU Affero General Public License   *
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.     *
+ ********************************************************************************/
 use log::error;
 
 mod config;
diff --git a/src/metrics.rs b/src/metrics.rs
index db7f853..d38aa7b 100644
--- a/src/metrics.rs
+++ b/src/metrics.rs
@@ -1,3 +1,22 @@
+/********************************************************************************
+ *   Prometheus exporter for monitoring network connectivity using icmp pings   *
+ *                                                                              *
+ *   Copyright (C) 2019-2020 Jan Christian Grünhage                             *
+ *   Copyright (C) 2020 Famedly GmbH                                            *
+ *                                                                              *
+ *   This program is free software: you can redistribute it and/or modify       *
+ *   it under the terms of the GNU Affero General Public License as             *
+ *   published by the Free Software Foundation, either version 3 of the         *
+ *   License, or (at your option) any later version.                            *
+ *                                                                              *
+ *   This program is distributed in the hope that it will be useful,            *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of             *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the               *
+ *   GNU Affero General Public License for more details.                        *
+ *                                                                              *
+ *   You should have received a copy of the GNU Affero General Public License   *
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.     *
+ ********************************************************************************/
 use crate::config::Config;
 use hyper::{
     header::CONTENT_TYPE,
diff --git a/src/ping.rs b/src/ping.rs
index 3fb8632..a704e86 100644
--- a/src/ping.rs
+++ b/src/ping.rs
@@ -1,3 +1,22 @@
+/********************************************************************************
+ *   Prometheus exporter for monitoring network connectivity using icmp pings   *
+ *                                                                              *
+ *   Copyright (C) 2019-2020 Jan Christian Grünhage                             *
+ *   Copyright (C) 2020 Famedly GmbH                                            *
+ *                                                                              *
+ *   This program is free software: you can redistribute it and/or modify       *
+ *   it under the terms of the GNU Affero General Public License as             *
+ *   published by the Free Software Foundation, either version 3 of the         *
+ *   License, or (at your option) any later version.                            *
+ *                                                                              *
+ *   This program is distributed in the hope that it will be useful,            *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of             *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the               *
+ *   GNU Affero General Public License for more details.                        *
+ *                                                                              *
+ *   You should have received a copy of the GNU Affero General Public License   *
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.     *
+ ********************************************************************************/
 use crate::config::Config;
 use futures_util::stream::StreamExt;
 use lazy_static::lazy_static;