diff --git a/ChangeLog b/ChangeLog
index a32b7d73b..02c47cdcc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2009-11-07  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	Better types for instance maps.
+
+	* src/ltlast/unop.hh (map): Use unop* as values.
+	* src/ltlast/binop.hh (map): Use binop* as values.
+	* src/ltlast/multop.hh (map): Use multop* as values.
+	* src/ltlast/automatop.hh (paircmp): Rename as tripletcmp.
+	(map): Use automaton* as values, not formula*.
+
 2009-11-07  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	Add missing instance_count() in automatop and eltl2tgba.
diff --git a/src/ltlast/automatop.hh b/src/ltlast/automatop.hh
index c25721462..a65842168 100644
--- a/src/ltlast/automatop.hh
+++ b/src/ltlast/automatop.hh
@@ -75,7 +75,7 @@ namespace spot
     protected:
       typedef std::pair<std::pair<nfa::ptr, bool>, vec*> triplet;
       /// Comparison functor used internally by ltl::automatop.
-      struct paircmp
+      struct tripletcmp
       {
 	bool
 	operator () (const triplet& p1, const triplet& p2) const
@@ -87,7 +87,7 @@ namespace spot
 	  return *p1.second < *p2.second;
 	}
       };
-      typedef std::map<triplet, formula*, paircmp> map;
+      typedef std::map<triplet, automatop*, tripletcmp> map;
       static map instances;
 
       automatop(const nfa::ptr, vec* v, bool negated);
diff --git a/src/ltlast/binop.hh b/src/ltlast/binop.hh
index 6bf9fec5d..9fdd195c7 100644
--- a/src/ltlast/binop.hh
+++ b/src/ltlast/binop.hh
@@ -73,7 +73,7 @@ namespace spot
     protected:
       typedef std::pair<formula*, formula*> pairf;
       typedef std::pair<type, pairf> pair;
-      typedef std::map<pair, formula*> map;
+      typedef std::map<pair, binop*> map;
       static map instances;
 
       binop(type op, formula* first, formula* second);
diff --git a/src/ltlast/multop.hh b/src/ltlast/multop.hh
index 7157b503b..97f531ba8 100644
--- a/src/ltlast/multop.hh
+++ b/src/ltlast/multop.hh
@@ -108,7 +108,7 @@ namespace spot
 	  return *p1.second < *p2.second;
 	}
       };
-      typedef std::map<pair, formula*, paircmp> map;
+      typedef std::map<pair, multop*, paircmp> map;
       static map instances;
 
       multop(type op, vec* v);
diff --git a/src/ltlast/unop.hh b/src/ltlast/unop.hh
index 0f522cb8f..8a650d77a 100644
--- a/src/ltlast/unop.hh
+++ b/src/ltlast/unop.hh
@@ -61,7 +61,7 @@ namespace spot
 
     protected:
       typedef std::pair<type, formula*> pair;
-      typedef std::map<pair, formula*> map;
+      typedef std::map<pair, unop*> map;
       static map instances;
 
       unop(type op, formula* child);