diff --git a/lemon/dimacs.h b/lemon/dimacs.h
--- a/lemon/dimacs.h
+++ b/lemon/dimacs.h
@@ -2,7 +2,7 @@
  *
  * This file is a part of LEMON, a generic C++ optimization library.
  *
- * Copyright (C) 2003-2008
+ * Copyright (C) 2003-2009
  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
  * (Egervary Research Group on Combinatorial Optimization, EGRES).
  *
@@ -334,7 +334,7 @@
     typedef typename Digraph::NodeIt NodeIt;
     typedef typename Digraph::ArcIt ArcIt;
 
-    if(!comment.empty()) 
+    if(!comment.empty())
       os << "c " << comment << std::endl;
     os << "p mat " << g.nodeNum() << " " << g.arcNum() << std::endl;