diff --git a/Solver/function.cpp b/Solver/function.cpp
index 47a6bdeed9e4fc2df41dc115fefdb6c17cc98753..818d30bd9acf42fe276f95d68d109ffc1aff077e 100644
--- a/Solver/function.cpp
+++ b/Solver/function.cpp
@@ -215,6 +215,7 @@ dataCacheDouble::dataCacheDouble(dataCacheMap *m, function *f):
   _cacheMap(*m),_value(m->getNbEvaluationPoints(),f->getNbCol()), _function(f)
 {
   m->addDataCacheDouble(this, f->isInvalitedOnElement());
+  _valid = false;
 }
 
 void dataCacheDouble::resize(int nrow)