diff --git a/src/historygraph.cpp b/src/historygraph.cpp
index 4407c896..6bcf0a96 100644
--- a/src/historygraph.cpp
+++ b/src/historygraph.cpp
@@ -1,3 +1,28 @@
+/******************************************************************************\
+ * Copyright (c) 2004-2019
+ *
+ * Author(s):
+ *  Volker Fischer
+ *  Peter L Jones <pljones@users.sf.net>
+ *
+ ******************************************************************************
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 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 General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+\******************************************************************************/
+
 #include "historygraph.h"
 
 /* Abstract class *************************************************************/
diff --git a/src/historygraph.h b/src/historygraph.h
index 198bcd4b..ccd43c9d 100644
--- a/src/historygraph.h
+++ b/src/historygraph.h
@@ -1,3 +1,28 @@
+/******************************************************************************\
+ * Copyright (c) 2004-2019
+ *
+ * Author(s):
+ *  Volker Fischer
+ *  Peter L Jones <pljones@users.sf.net>
+ *
+ ******************************************************************************
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 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 General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+\******************************************************************************/
+
 #ifndef HISTORYGRAPH_H
 #define HISTORYGRAPH_H