diff --git a/include/hpp/manipulation/device.hh b/include/hpp/manipulation/device.hh
index fefbe58aacdd8bdf16aa7f8d923f2fd71eeaac59..fec0b6ac73605a3e5d41e70e72d72ac40cb10e1c 100644
--- a/include/hpp/manipulation/device.hh
+++ b/include/hpp/manipulation/device.hh
@@ -67,6 +67,13 @@ namespace hpp {
           return core::Container <Element>::get (name);
         }
 
+        /// Check if a Container has a key.
+        template <typename Element>
+          bool has (const std::string& name) const
+        {
+          return core::Container <Element>::has (name);
+        }
+
         /// Get the keys of a container
         template <typename Element, typename ReturnType>
           ReturnType getKeys () const
diff --git a/include/hpp/manipulation/problem-solver.hh b/include/hpp/manipulation/problem-solver.hh
index a30be804ff298055e8475a69c6a658c7a45a2ac0..91c0fcd155d9ff166b6211c03df0c0001e87f784 100644
--- a/include/hpp/manipulation/problem-solver.hh
+++ b/include/hpp/manipulation/problem-solver.hh
@@ -136,6 +136,13 @@ namespace hpp {
           return Container <Element>::get (name);
         }
 
+        /// Check if a Container has a key.
+        template <typename Element>
+          bool has (const std::string& name) const
+        {
+          return core::Container <Element>::has (name);
+        }
+
         /// Add an element to a container
         template <typename Element>
           void add (const std::string& name, const Element& element)
diff --git a/src/problem-solver.cc b/src/problem-solver.cc
index 8772e0097366fa19ecd4aa361f208f7fb5b7365f..6700497b2afa6d581f0e677961505464031f8a69 100644
--- a/src/problem-solver.cc
+++ b/src/problem-solver.cc
@@ -161,21 +161,21 @@ namespace hpp {
 		  ConvexShapeContactComplementPtr_t > constraints
 	(ConvexShapeContactComplement::createPair
 	 (name, complementName, robot_));
-      JointAndShapes_t l = robot_->get <JointAndShapes_t>	(surface1);
-      if (l.empty ()) throw std::runtime_error
-			("First list of triangles not found.");
+      if (!robot_->has <JointAndShapes_t> (surface1))
+        throw std::runtime_error ("First list of triangles not found.");
+      JointAndShapes_t l = robot_->get <JointAndShapes_t> (surface1);
       for (JointAndShapes_t::const_iterator it = l.begin ();
 	   it != l.end(); ++it) {
 	constraints.first->addObject (ConvexShape (it->second, it->first));
       }
+
       // Search first robot triangles
-      l = robot_->get <JointAndShapes_t> (surface2);
-      if (l.empty ()) {
+      if (robot_->has <JointAndShapes_t> (surface2))
+        l = robot_->get <JointAndShapes_t> (surface2);
 	// and then environment triangles.
+      else if (has <JointAndShapes_t> (surface2))
 	l = get <JointAndShapes_t> (surface2);
-	if (l.empty ()) throw std::runtime_error
-			  ("Second list of triangles not found.");
-      }
+      else throw std::runtime_error ("Second list of triangles not found.");
       for (JointAndShapes_t::const_iterator it = l.begin ();
 	   it != l.end(); ++it) {
 	constraints.first->addFloor (ConvexShape (it->second, it->first));