diff --git a/Solver/function.cpp b/Solver/function.cpp
index 1193a69606ab017aeb41174af402eb3563463575..c1506b9bc256f63bc3bb3696ccd103275dbacbf6 100644
--- a/Solver/function.cpp
+++ b/Solver/function.cpp
@@ -7,11 +7,11 @@
 
 void dataCache::addMeAsDependencyOf (dataCache *newDep)
 {
-  _dependOnMe.insert(&newDep->_valid);
+  _dependOnMe.insert(newDep);
   newDep->_iDependOn.insert(this);
   for(std::set<dataCache*>::iterator it = _iDependOn.begin();
       it != _iDependOn.end(); it++) {
-    (*it)->_dependOnMe.insert(&newDep->_valid);
+    (*it)->_dependOnMe.insert(newDep);
     newDep->_iDependOn.insert(*it);
   }
 }
diff --git a/Solver/function.h b/Solver/function.h
index bc8bdc5c4a41479fc6412763e9cc974999d00383..268bccd3734f226c5ce94058d17c70e7b8c82a8e 100644
--- a/Solver/function.h
+++ b/Solver/function.h
@@ -30,8 +30,8 @@ class binding;
 // a node in the dependency tree. The usefull field is _dependOnMe which is the set of every other nodes that depend on me. When the value of this node change all nodes depending on this one are marked as "invalid" and will be recomputed the next time their data are accessed. To be able to maintain _dependOnMe up to date when a new node is inserted in the tree, we need _iDependOn list. So we do not really store a tree but instead each node contain a complete list of all it's parents and all it's children (and the parents of the parents of ... of its parents and the children of the children of ... of it's children). This way invalidate all the dependencies of a node is really fast and does not involve a complex walk accross the tree structure.
 class dataCache {
   friend class dataCacheMap;
-  // pointers to the "_valid" flag of all dataCache depending on me
-  std::set<bool*> _dependOnMe;
+  // pointers to all of the dataCache depending on me
+  std::set<dataCache*> _dependOnMe;
   std::set<dataCache*> _iDependOn;
 protected :
   bool _valid;
@@ -39,9 +39,9 @@ protected :
   inline void _invalidateDependencies()
   {
     // if this is too slow we can keep a C array cache of the _dependOnMe set
-    for(std::set<bool*>::iterator it = _dependOnMe.begin();
+    for(std::set<dataCache*>::iterator it = _dependOnMe.begin();
       it!=_dependOnMe.end(); it++)
-        **it=false;
+        (*it)->_valid=false;
   }
   dataCache() : _valid(false) {}
   virtual ~dataCache(){};