diff --git a/ChangeLog b/ChangeLog
index b566126cb..fb1b0725b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2004-04-13  Alexandre Duret-Lutz  <adl@src.lip6.fr>
 
+	* src/tgba/bdddict.hh (bdd_dict::annon_free_list): Hide from Swig.
+
 	* src/tgbaalgo/semptinesscheck.hh (counter_example): New class,
 	extracted from ...
 	(emptiness_check): ... here.
diff --git a/src/tgba/bdddict.hh b/src/tgba/bdddict.hh
index 0591ebcd8..691b7eb50 100644
--- a/src/tgba/bdddict.hh
+++ b/src/tgba/bdddict.hh
@@ -169,6 +169,9 @@ namespace spot
 
     void unregister_variable(vr_map::iterator& cur, const void* me);
 
+    // SWIG does not grok the following definition, no idea why.
+    // It's not important for the Python interface anyway.
+#ifndef SWIG
     class annon_free_list : public spot::free_list
     {
     public:
@@ -180,6 +183,7 @@ namespace spot
     private:
       bdd_dict* dict_;
     };
+#endif
 
     /// List of unused anonymous variable number for each automaton.
     typedef Sgi::hash_map<const void*, annon_free_list,