diff --git a/include/dynamic-graph/tracer-real-time.h b/include/dynamic-graph/tracer-real-time.h
index 2a4939ba4bd6be9e421800147cfa9e70c0f00b9b..19966a9e4209f04b306fe9a265c73d609a8b5071 100644
--- a/include/dynamic-graph/tracer-real-time.h
+++ b/include/dynamic-graph/tracer-real-time.h
@@ -54,7 +54,7 @@ namespace dynamicgraph
   {
   public:
     static const std::string CLASS_NAME;
-    virtual const std::string& getClassName ()
+    virtual const std::string& getClassName  () const
     {
       return CLASS_NAME;
     }
diff --git a/include/dynamic-graph/tracer.h b/include/dynamic-graph/tracer.h
index 486526f7ab16c9567e413a8169f327ca27cd9d1c..041563f8053fd4c80c631c243dafca5cc06fce77 100644
--- a/include/dynamic-graph/tracer.h
+++ b/include/dynamic-graph/tracer.h
@@ -43,7 +43,10 @@ namespace dynamicgraph
 
   public:
     static const std::string CLASS_NAME;
-    virtual const std::string& getClassName  () { return CLASS_NAME; }
+    virtual const std::string& getClassName () const
+    {
+      return CLASS_NAME;
+    }
 
   public:
     enum TraceStyle