diff --git a/ChangeLog b/ChangeLog
index 5feb95cf9..c24495c5e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2006-08-30  Alexandre Duret-Lutz  <adl@src.lip6.fr>
 
+	* evtgbaparse/evtgbaparse.yy, ltlparse/ltlparse.yy,
+	tgbaparse/tgbaparse.yy: Fix Bison warnings about unset $$.
+
 	* src/tgbaparse/Makefile.am (tgbaparse_HEADERS): Also
 	install location.hh and position.hh, since we no longer share
 	those of ltlvisit.
diff --git a/src/evtgbaparse/evtgbaparse.yy b/src/evtgbaparse/evtgbaparse.yy
index d0be3cc40..8abdf1d13 100644
--- a/src/evtgbaparse/evtgbaparse.yy
+++ b/src/evtgbaparse/evtgbaparse.yy
@@ -1,4 +1,4 @@
-/* Copyright (C) 2004, 2005  Laboratoire d'Informatique de Paris 6 (LIP6),
+/* Copyright (C) 2004, 2005, 2006  Laboratoire d'Informatique de Paris 6 (LIP6),
 ** département Systèmes Répartis Coopératifs (SRC), Université Pierre
 ** et Marie Curie.
 **
@@ -85,6 +85,7 @@ line: strident ',' strident ',' strident ',' acc_list ';'
 string: STRING
        | UNTERMINATED_STRING
        {
+	 $$ = $1;
 	 error_list.push_back(spot::evtgba_parse_error(@1,
 						     "unterminated string"));
        }
@@ -97,7 +98,8 @@ acc_list:
        }
        | acc_list strident
        {
-	 $1->insert(spot::rsymbol(*$2));
+	 $$ = $1;
+	 $$->insert(spot::rsymbol(*$2));
 	 delete $2;
        }
        ;
@@ -121,7 +123,7 @@ init_decl:
 %%
 
 void
-evtgbayy::parser::error(const location_type& location, 
+evtgbayy::parser::error(const location_type& location,
 			const std::string& message)
 {
   error_list.push_back(spot::evtgba_parse_error(location, message));
diff --git a/src/ltlparse/ltlparse.yy b/src/ltlparse/ltlparse.yy
index 6e8efce8f..ce74666d0 100644
--- a/src/ltlparse/ltlparse.yy
+++ b/src/ltlparse/ltlparse.yy
@@ -1,6 +1,6 @@
-/* Copyright (C) 2003, 2004, 2005  Laboratoire d'Informatique de Paris 6 (LIP6),
-** département Systèmes Répartis Coopératifs (SRC), Université Pierre
-** et Marie Curie.
+/* Copyright (C) 2003, 2004, 2005, 2006 Laboratoire d'Informatique de
+** Paris 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
+** Université Pierre et Marie Curie.
 **
 ** This file is part of Spot, a model checking library.
 **
@@ -103,14 +103,14 @@ using namespace spot::ltl;
 
 %nonassoc OP_POST_NEG OP_POST_POS
 
-%type <ltl> result subformula
+%type <ltl> subformula
 
 /* At the time of writing (2004-01-05) there is a bug in CVS Bison: if
    you give a token (such a ATOMIC_PROP) a name (such as "atomic
    proposition"), then the %destructor should refer to that name.
    References to ATOMIC_PROP are silently ignored.  */
 %destructor { delete $$; } "atomic proposition"
-%destructor { spot::ltl::destroy($$); } result subformula
+%destructor { spot::ltl::destroy($$); } subformula
 
 %printer { debug_stream() << *$$; } "atomic proposition"
 
diff --git a/src/tgbaparse/tgbaparse.yy b/src/tgbaparse/tgbaparse.yy
index d11841145..7fe3b4252 100644
--- a/src/tgbaparse/tgbaparse.yy
+++ b/src/tgbaparse/tgbaparse.yy
@@ -152,6 +152,7 @@ line: strident ',' strident ',' condition ',' acc_list ';'
 string: STRING
        | UNTERMINATED_STRING
        {
+	 $$ = $1;
 	 error_list.push_back(spot::tgba_parse_error(@1,
 						     "unterminated string"));
        }
@@ -219,7 +220,7 @@ acc_decl:
 %%
 
 void
-tgbayy::parser::error(const location_type& location, 
+tgbayy::parser::error(const location_type& location,
 		      const std::string& message)
 {
   error_list.push_back(spot::tgba_parse_error(location, message));