diff --git a/src/flux_function.h b/src/flux_function.h
--- a/src/flux_function.h
+++ b/src/flux_function.h
@@ -1,12 +1,30 @@
 /*
- *  flux_function.h
- *  VirtualLeaf
+ *
+ *  $Id$
+ *
+ *  This file is part of the Virtual Leaf.
+ *
+ *  The Virtual Leaf 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 3 of the License, or
+ *  (at your option) any later version.
  *
- *  Created by Roeland Merks on 07-06-10.
- *  Copyright 2010 __MyCompanyName__. All rights reserved.
+ *  The Virtual Leaf 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 the Virtual Leaf.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Copyright 2010 Roeland Merks.
  *
  */
 
+
+#ifndef _FLUX_FUNCTION_h_
+#define _FLUX_FUNCTION_h_
+
 // This header file defines a macro "SumFluxFromWalls" that attempts to hide this 
 // horrendously confusing member function wrapper construct from VirtualLeaf's end users
 
@@ -20,3 +38,4 @@
 #define SumFluxFromWalls( _vleafcellp_, _flux_function_ ) \
 (( _vleafcellp_->ReduceCellAndWalls<double>( far_3_arg_mem_fun( *this, &_flux_function_ ) ) ))
 
+#endif