diff --git a/doc/Doxyfile.extra.in b/doc/Doxyfile.extra.in
index 9ca64de3f434a2e125f080fe33b7d42657e5d5f8..6ad3914fd15846e221733eb0289056da7f506139 100644
--- a/doc/Doxyfile.extra.in
+++ b/doc/Doxyfile.extra.in
@@ -8,3 +8,5 @@ ALIASES   += Link{1}="\ref \1"
 ALIASES   += Link{2}="\ref \1 \"\2\""
 ALIASES   += LHPP{2}="\Link{hpp::\1::\2,\2}"
 ALIASES   += LPinocchio{1}="\LHPP{pinocchio,\1}"
+
+EXTRA_PACKAGES = {amsmath}
diff --git a/src/problem.cc b/src/problem.cc
index aa18b9b8799822bc1d5ab19c44122e1ad26a6c8e..d22119a2e7e2eb177ae4c74f2828c28d26ca3407 100644
--- a/src/problem.cc
+++ b/src/problem.cc
@@ -101,7 +101,7 @@ namespace hpp {
     {
       pvFactory_ = factory;
       pvTol_ = tol;
-      if (graph_) graph_->setDirty();
+      if (graph_) graph_->invalidate();
     }
 
     void Problem::checkProblem () const
diff --git a/tests/test-constraintgraph.cc b/tests/test-constraintgraph.cc
index 6de25dd77ab9c6dc624399a5f15b1d640fdde04d..8fd07b7c57712012d3fa5e95321df8f5df12da4c 100644
--- a/tests/test-constraintgraph.cc
+++ b/tests/test-constraintgraph.cc
@@ -148,7 +148,7 @@ BOOST_AUTO_TEST_CASE (Initialization)
   initialize(true);
   hpp::manipulation::DevicePtr_t robot(graph_->robot());
   graph_->addNumericalConstraint(LockedJoint::create
-    (robot->jointAt(1), LiegroupElement(LiegroupSpace::R1())));
+    (robot->jointAt(1), LiegroupElement(LiegroupSpace::R1(true))));
   for (std::size_t i=0; i < components.size(); ++i)
   {
     EdgePtr_t edge(HPP_DYNAMIC_PTR_CAST(Edge, components[i]));