diff --git a/owlps-positioner/building.cc b/owlps-positioner/building.cc
index 5f3dc62..89f55c2 100644
--- a/owlps-positioner/building.cc
+++ b/owlps-positioner/building.cc
@@ -75,7 +75,7 @@ void Building::add_area(Area *&area)
       return ;
     }
 
-  areas[area_name] = const_cast<Area*>(area) ;
+  areas[area_name] = area ;
 }
 
 
diff --git a/owlps-positioner/building.hh b/owlps-positioner/building.hh
index a30bf3f..a19bb28 100644
--- a/owlps-positioner/building.hh
+++ b/owlps-positioner/building.hh
@@ -29,7 +29,7 @@ class Building
 protected:
   std::string name ;
   /// List of Area contained in the Building
-  std::unordered_map<std::string, Area*> areas ;
+  std::unordered_map<std::string, const Area*> areas ;
   /// List of Waypoint in the Building
   std::unordered_set<Waypoint*> waypoints ;
 
@@ -46,7 +46,8 @@ public:
   /** @name Read accessors */
   //@{
   const std::string& get_name(void) const ;
-  const std::unordered_map<std::string, Area*>& get_areas(void) const ;
+  const std::unordered_map<std::string, const Area*>&
+  get_areas(void) const ;
   const std::unordered_set<Waypoint*>& get_waypoints(void) const ;
   //@}
 
@@ -81,7 +82,7 @@ inline const std::string& Building::get_name() const
 }
 
 
-inline const std::unordered_map<std::string, Area*>&
+inline const std::unordered_map<std::string, const Area*>&
 Building::get_areas() const
 {
   return areas ;
diff --git a/owlps-positioner/stock.cc b/owlps-positioner/stock.cc
index b26c005..df6ccce 100644
--- a/owlps-positioner/stock.cc
+++ b/owlps-positioner/stock.cc
@@ -100,7 +100,8 @@ const Area* Stock::in_which_area_is(const Point3D &point)
 {
   for (auto b = buildings.begin() ; b != buildings.end() ; ++b)
     {
-      const unordered_map<string, Area*> &areas = b->second.get_areas() ;
+      const unordered_map<string, const Area*> &areas =
+        b->second.get_areas() ;
       for (auto a = areas.begin() ; a != areas.end() ; ++a)
         if (a->second->contains_point(point))
           return a->second ;
diff --git a/owlps-positioner/tests/building_test.hh b/owlps-positioner/tests/building_test.hh
index 6bcfd21..41f1884 100644
--- a/owlps-positioner/tests/building_test.hh
+++ b/owlps-positioner/tests/building_test.hh
@@ -41,7 +41,7 @@ public:
     // Simple read accessors
     Building b1 ;
     TS_ASSERT_EQUALS(b1.get_name(), "Unnamed building") ;
-    std::unordered_map<std::string, Area*> areas1 ;
+    std::unordered_map<std::string, const Area*> areas1 ;
     TS_ASSERT_EQUALS(b1.get_areas(), areas1) ;
     std::unordered_set<Waypoint*> waypoints1 ;
     TS_ASSERT_EQUALS(b1.get_waypoints(), waypoints1) ;
diff --git a/owlps-positioner/tests/topologyreadercsv_test.hh b/owlps-positioner/tests/topologyreadercsv_test.hh
index d33924f..972e37f 100644
--- a/owlps-positioner/tests/topologyreadercsv_test.hh
+++ b/owlps-positioner/tests/topologyreadercsv_test.hh
@@ -84,7 +84,7 @@ public:
 
     TS_ASSERT_EQUALS(building1->get_areas().size(), 2u) ;
 
-    Area *area_ptr ;
+    const Area *area_ptr ;
     area_ptr = building1->get_areas().find("My room #1")->second ;
     Area area1(building1, "My room #1",
                Point3D(1,2,3), Point3D(9,8,7)) ;