diff --git a/owlps-positioner/area.hh b/owlps-positioner/area.hh
index 0ba78b0..441f182 100644
--- a/owlps-positioner/area.hh
+++ b/owlps-positioner/area.hh
@@ -35,7 +35,7 @@ protected:
   void reorder_coordinates(void) ;
 
 public:
-  Area(const Building *const _building = NULL,
+  Area(const Building *const _building = nullptr,
        const std::string &_name = "Unnamed area",
        const Point3D &p1 = Point3D(0,0,0),
        const Point3D &p2 = Point3D(0,0,0)) ;
diff --git a/owlps-positioner/autocalibrationline.cc b/owlps-positioner/autocalibrationline.cc
index 77703ea..9c938e5 100644
--- a/owlps-positioner/autocalibrationline.cc
+++ b/owlps-positioner/autocalibrationline.cc
@@ -33,14 +33,14 @@ using namespace std ;
 /**
  * @param _point The coordinates of the reference point to generate.
  * @param _cp1 The first capture point (receiver) to use the measurements
- * of to generate the reference points; it cannot be NULL.
+ * of to generate the reference points; it cannot be null.
  * @param _cp2 The second receiver capture point (optional).
  */
 AutocalibrationLine::AutocalibrationLine(
   const Point3D &_point,
   const CapturePoint *const _cp1, const CapturePoint *const _cp2):
   Autocalibration(_point), cp1(_cp1), cp2(_cp2),
-  trx_cp(NULL), trx_rp(NULL)
+  trx_cp(nullptr), trx_rp(nullptr)
 {
   assert(cp1) ;
 }
@@ -120,7 +120,7 @@ void AutocalibrationLine::sort_reference_cps()
         Stock::get_reference_point(ref->second.get_coordinates()) ;
       const vector<CalibrationRequest*> &ref_cr = ref_rp.get_requests() ;
       /* Search for the first measurement made by RX in ref_rp */
-      const Measurement *rx_measurement = NULL ;
+      const Measurement *rx_measurement = nullptr ;
       const string &rx_mac = rx->second.get_mac_addr() ;
       for (auto cr = ref_cr.begin() ; cr != ref_cr.end() ; ++cr)
         {
@@ -153,7 +153,7 @@ void AutocalibrationLine::compute_multi_packet_ss()
   const vector<CalibrationRequest*> &ref_cr = trx_rp->get_requests() ;
 
   /* Search for the first measurement made by RX in trx_rp */
-  const Measurement *rx_measurement = NULL ;
+  const Measurement *rx_measurement = nullptr ;
   vector<CalibrationRequest*>::const_iterator cr ;
   const string &rx_mac = rx->second.get_mac_addr() ;
   for (cr = ref_cr.begin() ; cr != ref_cr.end() ; ++cr)
diff --git a/owlps-positioner/autocalibrationline.hh b/owlps-positioner/autocalibrationline.hh
index d8154a3..10b66c5 100644
--- a/owlps-positioner/autocalibrationline.hh
+++ b/owlps-positioner/autocalibrationline.hh
@@ -49,7 +49,7 @@ protected:
 public:
   AutocalibrationLine(const Point3D &_point,
                       const CapturePoint *const _cp1,
-                      const CapturePoint *const _cp2 = NULL) ;
+                      const CapturePoint *const _cp2 = nullptr) ;
 } ;
 
 #endif // _OWLPS_POSITIONING_AUTOCALIBRATIONLINE_HH_
diff --git a/owlps-positioner/autocalibrationmesh.cc b/owlps-positioner/autocalibrationmesh.cc
index d3043da..7b299a5 100644
--- a/owlps-positioner/autocalibrationmesh.cc
+++ b/owlps-positioner/autocalibrationmesh.cc
@@ -187,7 +187,7 @@ void AutocalibrationMesh::compute_multi_packet_ss()
   const vector<CalibrationRequest*> &ref1_cr = ref1_rp.get_requests() ;
 
   /* Search for the first measurement made by RX in ref1_rp */
-  const Measurement *rx_measurement = NULL ;
+  const Measurement *rx_measurement = nullptr ;
   vector<CalibrationRequest*>::const_iterator cr ;
   const string &rx_mac = rx->second.get_mac_addr() ;
   for (cr = ref1_cr.begin() ; cr != ref1_cr.end() ; ++cr)
diff --git a/owlps-positioner/building.cc b/owlps-positioner/building.cc
index bf45b88..ca3ec90 100644
--- a/owlps-positioner/building.cc
+++ b/owlps-positioner/building.cc
@@ -50,7 +50,7 @@ Building::~Building()
 
 
 /**
- * If `area` is NULL, nothing is done.
+ * If `area` is null, nothing is done.
  * If `area` is a pointer to an Area that is already stored in #areas,
  * nothing is done.
  * If `area` has the same name as (but is not identical to) an Area that
diff --git a/owlps-positioner/building.hh b/owlps-positioner/building.hh
index 8d4b354..b8051d8 100644
--- a/owlps-positioner/building.hh
+++ b/owlps-positioner/building.hh
@@ -107,7 +107,7 @@ inline void Building::set_name(const std::string &_name)
 
 
 /**
- * @param wp A pointer to the Waypoint to add. If `wp` is NULL,
+ * @param wp A pointer to the Waypoint to add. If `wp` is null,
  * nothing will be added.
  */
 inline void Building::add_waypoint(Waypoint *const wp)
diff --git a/owlps-positioner/calibrationrequest.cc b/owlps-positioner/calibrationrequest.cc
index 5683202..d34ac6a 100644
--- a/owlps-positioner/calibrationrequest.cc
+++ b/owlps-positioner/calibrationrequest.cc
@@ -20,7 +20,7 @@
 
 
 CalibrationRequest::CalibrationRequest(const uint_fast8_t _type):
-  reference_point(NULL), direction(Direction())
+  reference_point(nullptr), direction(Direction())
 {
   type = _type ;
 }
@@ -57,7 +57,7 @@ void CalibrationRequest::reference_point_backward_link() const
 void CalibrationRequest::clear()
 {
   Request::clear() ;
-  reference_point = NULL ;
+  reference_point = nullptr ;
   direction.clear() ;
 }
 
diff --git a/owlps-positioner/calibrationrequest.hh b/owlps-positioner/calibrationrequest.hh
index b877b44..3e74c7a 100644
--- a/owlps-positioner/calibrationrequest.hh
+++ b/owlps-positioner/calibrationrequest.hh
@@ -37,7 +37,7 @@ public:
     direction(source.direction) {}
 
   CalibrationRequest(const Request &source,
-                     ReferencePoint *const _reference_point = NULL,
+                     ReferencePoint *const _reference_point = nullptr,
                      const Direction &_direction = Direction(),
                      const uint_fast8_t _type = OWL_REQUEST_AUTOCALIBRATION) ;
 
diff --git a/owlps-positioner/csvstringreader.cc b/owlps-positioner/csvstringreader.cc
index e577701..0a49a87 100644
--- a/owlps-positioner/csvstringreader.cc
+++ b/owlps-positioner/csvstringreader.cc
@@ -30,7 +30,7 @@ using boost::bad_lexical_cast ;
 
 CSVStringReader::
 CSVStringReader(const std::string &_str, const char _separator):
-  separator(_separator), current_token(NULL), current_field_nb(0)
+  separator(_separator), current_token(nullptr), current_field_nb(0)
 {
   set_str(_str) ;
 }
diff --git a/owlps-positioner/csvstringreader.hh b/owlps-positioner/csvstringreader.hh
index dde8358..8ac084e 100644
--- a/owlps-positioner/csvstringreader.hh
+++ b/owlps-positioner/csvstringreader.hh
@@ -39,7 +39,7 @@ protected:
 
 public:
   CSVStringReader(const char _separator = ';'):
-    separator(_separator), current_token(NULL), current_field_nb(0) {}
+    separator(_separator), current_token(nullptr), current_field_nb(0) {}
 
   CSVStringReader(const std::string &_str, const char _separator = ';') ;
 
diff --git a/owlps-positioner/frbhmbasic.hh b/owlps-positioner/frbhmbasic.hh
index 5f2e915..e2eeb47 100644
--- a/owlps-positioner/frbhmbasic.hh
+++ b/owlps-positioner/frbhmbasic.hh
@@ -28,7 +28,7 @@ protected:
 
 public:
   FRBHMBasic(void):
-    PositioningAlgorithm("FRBHMBasic"), closest_in_ss(NULL) {}
+    PositioningAlgorithm("FRBHMBasic"), closest_in_ss(nullptr) {}
   ~FRBHMBasic(void) {}
 
   /** @name Operations */
diff --git a/owlps-positioner/input.cc b/owlps-positioner/input.cc
index 9cb20aa..12e11d7 100644
--- a/owlps-positioner/input.cc
+++ b/owlps-positioner/input.cc
@@ -32,7 +32,7 @@ using namespace std ;
 
 
 Input::Input():
-  medium(NULL)
+  medium(nullptr)
 {
   initialise_input_medium() ;
   initialise_log_media() ;
diff --git a/owlps-positioner/inputmedium.cc b/owlps-positioner/inputmedium.cc
index b1e8a59..5c07294 100644
--- a/owlps-positioner/inputmedium.cc
+++ b/owlps-positioner/inputmedium.cc
@@ -78,7 +78,7 @@ void InputMedium::clear_current_request()
   else
     {
       delete current_request ;
-      current_request = NULL ;
+      current_request = nullptr ;
       current_request = new Request() ;
     }
 }
@@ -174,7 +174,7 @@ void InputMedium::current_request_to_calibration_request(
     }
 
   Request *tmp = current_request ;
-  current_request = NULL ;
+  current_request = nullptr ;
   current_request =
     new CalibrationRequest(*tmp,
                            const_cast<ReferencePoint*>(reference_point),
diff --git a/owlps-positioner/inputudpsocket.cc b/owlps-positioner/inputudpsocket.cc
index 2621122..d2bd28e 100644
--- a/owlps-positioner/inputudpsocket.cc
+++ b/owlps-positioner/inputudpsocket.cc
@@ -101,7 +101,7 @@ bool InputUDPSocket::fill_current_request()
   // Read the main request data
   owl_request request ;
   ssize_t nread = recvfrom(sockfd, &request, sizeof(request), 0,
-                           NULL, NULL) ;
+                           nullptr, nullptr) ;
   if (nread <= 0)
     {
       cerr << "InputUDPSocket: No request received!" << endl ;
@@ -181,7 +181,7 @@ bool InputUDPSocket::fill_current_request()
   for (int i = 0 ; i < request.nb_info ; ++i)
     {
       nread = recvfrom(sockfd, &request_info, sizeof(request_info), 0,
-                       NULL, NULL) ;
+                       nullptr, nullptr) ;
       if (nread <= 0)
         {
           cerr << "No request info received!" << endl ;
diff --git a/owlps-positioner/measurement.cc b/owlps-positioner/measurement.cc
index e651f80..9f9a4e0 100644
--- a/owlps-positioner/measurement.cc
+++ b/owlps-positioner/measurement.cc
@@ -115,7 +115,7 @@ void Measurement::merge(const Measurement &source)
 
 
 /**
- * - #cp is not deleted, only initialised to NULL.
+ * - #cp is not deleted, only initialised to nullptr.
  * - #ss_list is cleared.
  * - average and variance variables are reset to 0.
  */
@@ -129,7 +129,7 @@ void Measurement::clear()
   variance_mw_m2 = 0 ;
   variance_dbm_m2 = 0 ;
   variance_size = 0 ;
-  cp = NULL ;
+  cp = nullptr ;
 }
 
 
diff --git a/owlps-positioner/measurement.hh b/owlps-positioner/measurement.hh
index 8f7446f..731b11f 100644
--- a/owlps-positioner/measurement.hh
+++ b/owlps-positioner/measurement.hh
@@ -65,7 +65,7 @@ protected:
 
 
 public:
-  Measurement(const CapturePoint *const _cp = NULL):
+  Measurement(const CapturePoint *const _cp = nullptr):
     cp(_cp), average_dbm(0),
     average_mw(0), variance_mw(0), variance_dbm(0),
     variance_mw_m2(0), variance_dbm_m2(0), variance_size(0) {}
diff --git a/owlps-positioner/owlps-positionerd.cc b/owlps-positioner/owlps-positionerd.cc
index fee0bb3..c79b68f 100644
--- a/owlps-positioner/owlps-positionerd.cc
+++ b/owlps-positioner/owlps-positionerd.cc
@@ -49,9 +49,9 @@ int main(const int argc, const char **const argv)
       action.sa_flags = 0 ;
       sigemptyset(&action.sa_mask) ;
       action.sa_handler = owl_sigint_handler ;
-      sigaction(SIGINT, &action, NULL) ;
+      sigaction(SIGINT, &action, nullptr) ;
       action.sa_handler = owl_sigterm_handler ;
-      sigaction(SIGTERM, &action, NULL) ;
+      sigaction(SIGTERM, &action, nullptr) ;
 
       /* Run! */
       Positioning positioning ;
diff --git a/owlps-positioner/realposition.cc b/owlps-positioner/realposition.cc
index 737d825..fe649b2 100644
--- a/owlps-positioner/realposition.cc
+++ b/owlps-positioner/realposition.cc
@@ -20,7 +20,7 @@
 
 Result RealPosition::compute(const Request &request)
 {
-  const Point3D *coordinates = NULL ;
+  const Point3D *coordinates = nullptr ;
 
   const CalibrationRequest *calibration_request =
     dynamic_cast<const CalibrationRequest*>(&request) ;
diff --git a/owlps-positioner/referencepoint.hh b/owlps-positioner/referencepoint.hh
index c7df183..e3030eb 100644
--- a/owlps-positioner/referencepoint.hh
+++ b/owlps-positioner/referencepoint.hh
@@ -124,7 +124,7 @@ std::vector<CalibrationRequest*>& ReferencePoint::get_requests() const
 
 /**
  * @param r A pointer to the CalibrationRequest to add. If it is
- * NULL, nothing will be done.
+ * null, nothing will be done.
  * The memory pointed by this pointer must not be deallocated before
  * the ReferencePoint destruction (do *not* pass a pointer to a local
  * variable!).
diff --git a/owlps-positioner/request.cc b/owlps-positioner/request.cc
index a08c3c1..68ff215 100644
--- a/owlps-positioner/request.cc
+++ b/owlps-positioner/request.cc
@@ -32,7 +32,7 @@ Request::Request(
 ):
   type(OWL_REQUEST_UNDEFINED), nb_packets(1),
   mobile(_mobile), time_sent(_time_sent),
-  measurements(_measurements), real_position(NULL)
+  measurements(_measurements), real_position(nullptr)
 {
   received_now() ;
 }
@@ -41,7 +41,7 @@ Request::Request(
 Request::Request(const unordered_map<string, Measurement>
                  &_measurements):
   type(OWL_REQUEST_UNDEFINED), nb_packets(1),
-  mobile(NULL), measurements(_measurements), real_position(NULL)
+  mobile(nullptr), measurements(_measurements), real_position(nullptr)
 {
   received_now() ;
 }
@@ -52,8 +52,8 @@ Request::Request(
   const unordered_map<string, Measurement> &_measurements
 ):
   type(OWL_REQUEST_UNDEFINED), nb_packets(1),
-  mobile(NULL), time_sent(_time_sent),
-  measurements(_measurements), real_position(NULL)
+  mobile(nullptr), time_sent(_time_sent),
+  measurements(_measurements), real_position(nullptr)
 {
   received_now() ;
 }
@@ -63,7 +63,7 @@ Request::Request(const Request &source):
   type(source.type), nb_packets(source.nb_packets),
   mobile(source.mobile), time_sent(source.time_sent),
   time_received(source.time_received),
-  measurements(source.measurements), real_position(NULL)
+  measurements(source.measurements), real_position(nullptr)
 {
   if (source.real_position)
     real_position = new Point3D(*source.real_position) ;
@@ -86,7 +86,7 @@ Request::~Request()
 
 /**
  * @param mac_receiver The MAC address of the receiver CP.
- * @returns A pointer on the found measurement, or NULL if no
+ * @returns A pointer on the found measurement, or nullptr if no
  * measurement was made by this CP.
  */
 const Measurement*
@@ -95,7 +95,7 @@ Request::get_measurement(const string &mac_receiver) const
   auto m = measurements.find(mac_receiver) ;
   if (m != measurements.end())
     return &m->second ;
-  return NULL ;
+  return nullptr ;
 }
 
 
@@ -108,7 +108,7 @@ inline void Request::clear_real_position()
   if (real_position)
     {
       delete real_position ;
-      real_position = NULL ;
+      real_position = nullptr ;
     }
 }
 
@@ -125,7 +125,8 @@ void Request::set_real_position(const Point3D &_real_position)
 /**
  * - #nb_packets is set to 1 (this is the default value when
  *   constructing a Request).
- * - #mobile is NULLified, but the value it pointed to is not deleted.
+ * - #mobile is set to nullptr, but the value it pointed to is not
+ *   deleted.
  * - The fields of #time_sent and #time_received are initialised to 0.
  * - #measurements is cleared.
  */
@@ -133,7 +134,7 @@ void Request::clear()
 {
   type = OWL_REQUEST_UNDEFINED ;
   nb_packets = 1 ;
-  mobile = NULL ;
+  mobile = nullptr ;
   time_sent.clear() ;
   time_received.clear() ;
   measurements.clear() ;
@@ -195,7 +196,7 @@ bool Request::operator==(const Request &source) const
   else if (real_position && source.real_position)
     real_position_equal = *real_position == *source.real_position ;
   else
-    real_position_equal = false ; // one of the two is NULL
+    real_position_equal = false ; // one of the two is null
 
   return
     real_position_equal &&
diff --git a/owlps-positioner/request.hh b/owlps-positioner/request.hh
index 02002b5..d1ab7b8 100644
--- a/owlps-positioner/request.hh
+++ b/owlps-positioner/request.hh
@@ -66,7 +66,7 @@ protected:
   using measurements_list = std::unordered_map<std::string, Measurement> ;
 
 public:
-  Request(const Mobile *const _mobile = NULL,
+  Request(const Mobile *const _mobile = nullptr,
           const Timestamp &_time_sent = Timestamp(),
           const std::unordered_map<std::string, Measurement>
           &_measurements = measurements_list()) ;
diff --git a/owlps-positioner/result.hh b/owlps-positioner/result.hh
index 626a64f..79bcd23 100644
--- a/owlps-positioner/result.hh
+++ b/owlps-positioner/result.hh
@@ -36,7 +36,7 @@ protected:
   float error ;
 
 public:
-  Result(const Request *const _request = NULL,
+  Result(const Request *const _request = nullptr,
          const std::string &_algorithm = "UnknownAlgorithm"):
     request(_request), algorithm(_algorithm), error(-1) {}
   Result(const Request *const _request, const std::string &_algorithm,
diff --git a/owlps-positioner/resultlist.hh b/owlps-positioner/resultlist.hh
index 31e7ec0..ed7ca35 100644
--- a/owlps-positioner/resultlist.hh
+++ b/owlps-positioner/resultlist.hh
@@ -30,7 +30,7 @@ protected:
   std::vector<Result> results ;
 
 public:
-  ResultList(const Request *const _request = NULL,
+  ResultList(const Request *const _request = nullptr,
              const std::vector<Result> &_results = std::vector<Result>()):
     request(_request), results(_results) {}
   ResultList(const ResultList &source):
diff --git a/owlps-positioner/stock.cc b/owlps-positioner/stock.cc
index be4fcff..d6c649d 100644
--- a/owlps-positioner/stock.cc
+++ b/owlps-positioner/stock.cc
@@ -94,7 +94,7 @@ const Building& Stock::get_building(const string &name)
 
 /**
  * @returns A pointer to the first Area in which `point` was found.
- * @returns NULL if `point` does not belong to any Area.
+ * @returns nullptr if `point` does not belong to any Area.
  */
 const Area* Stock::in_which_area_is(const Point3D &point)
 {
@@ -107,7 +107,7 @@ const Area* Stock::in_which_area_is(const Point3D &point)
           return a->second ;
     }
 
-  return NULL ;
+  return nullptr ;
 }
 
 
@@ -323,7 +323,7 @@ double Stock::cp_matrix_get_ss(const std::string &mac_transmitter,
 
 /**
  * @returns A const pointer to the CP `coord` is the coordinates of.
- * @returns NULL if `coord` is not the coordinates of any CP.
+ * @returns nullptr if `coord` is not the coordinates of any CP.
  */
 const CapturePoint* Stock::is_cp_coordinate(const Point3D &coord)
 {
@@ -331,7 +331,7 @@ const CapturePoint* Stock::is_cp_coordinate(const Point3D &coord)
     if (cp->second.get_coordinates() == coord)
       return &cp->second ;
 
-  return NULL ;
+  return nullptr ;
 }
 
 
@@ -497,7 +497,7 @@ void Stock::generate_reference_points_line()
   CSVStringReader path_parser(path_csv) ;
   Point3D p ;
   vector<Point3D> read_points ;
-  const CapturePoint *cp1 = NULL ;
+  const CapturePoint *cp1 = nullptr ;
 
   // Read points until the first CP coordinate
   while (path_parser.read_point3d(p))
@@ -533,7 +533,7 @@ void Stock::generate_reference_points_line()
     }
 
   // Read the next points and generate the RPs
-  const CapturePoint *cp2 = NULL ;
+  const CapturePoint *cp2 = nullptr ;
   while (path_parser.read_point3d(p))
     {
       cp2 = Stock::is_cp_coordinate(p) ;
@@ -566,7 +566,7 @@ void Stock::generate_reference_points_line()
         }
 
       cp1 = cp2 ;
-      cp2 = NULL ;
+      cp2 = nullptr ;
     }
 
   // Generate the last RPs (after the last RP)
diff --git a/owlps-positioner/stock.hh b/owlps-positioner/stock.hh
index 42e129b..8c1a9bb 100644
--- a/owlps-positioner/stock.hh
+++ b/owlps-positioner/stock.hh
@@ -73,7 +73,7 @@ private:
   static void generate_interpolated_reference_points(
     const Point3D &start, const Point3D &end,
     const CapturePoint *const cp1,
-    const CapturePoint *const cp2 = NULL) ;
+    const CapturePoint *const cp2 = nullptr) ;
   /// Generates reference points according to a list
   static void generate_reference_points_list(void) ;
   /// Generates a single reference point
diff --git a/owlps-positioner/tests/area_test.hh b/owlps-positioner/tests/area_test.hh
index f332794..c301f87 100644
--- a/owlps-positioner/tests/area_test.hh
+++ b/owlps-positioner/tests/area_test.hh
@@ -24,7 +24,7 @@ public:
   {
     // Default constructor
     Area a1 ;
-    Area a2(NULL, "Unnamed area", Point3D(0,0,0), Point3D(0,0,0)) ;
+    Area a2(nullptr, "Unnamed area", Point3D(0,0,0), Point3D(0,0,0)) ;
     TS_ASSERT_EQUALS(a1, a2) ;
 
     // Copy constructor
diff --git a/owlps-positioner/tests/measurement_test.hh b/owlps-positioner/tests/measurement_test.hh
index bf4c355..752b068 100644
--- a/owlps-positioner/tests/measurement_test.hh
+++ b/owlps-positioner/tests/measurement_test.hh
@@ -24,7 +24,7 @@ public:
     // Default constructor
     Measurement m00 ;
     std::map<pkt_id_t, ss_t> vi1 ;
-    Measurement m01(NULL) ;
+    Measurement m01(nullptr) ;
     m01.add_ss_list(vi1) ;
     TS_ASSERT_EQUALS(m00, m01) ;
 
diff --git a/owlps-positioner/tests/result_test.hh b/owlps-positioner/tests/result_test.hh
index 2c4fe31..1e68f7f 100644
--- a/owlps-positioner/tests/result_test.hh
+++ b/owlps-positioner/tests/result_test.hh
@@ -24,8 +24,8 @@ public:
   {
     // Default constructor
     Result result1 ;
-    Result result2(NULL) ;
-    Result result3(NULL, "UnknownAlgorithm") ;
+    Result result2(nullptr) ;
+    Result result3(nullptr, "UnknownAlgorithm") ;
     TS_ASSERT_EQUALS(result1, result2) ;
     TS_ASSERT_EQUALS(result1, result3) ;
 
diff --git a/owlps-positioner/tests/textfilereader_test.hh b/owlps-positioner/tests/textfilereader_test.hh
index 5026c3f..1996ce5 100644
--- a/owlps-positioner/tests/textfilereader_test.hh
+++ b/owlps-positioner/tests/textfilereader_test.hh
@@ -54,7 +54,7 @@ public:
     output_file.close() ;
 
     std::string line ;
-    TextFileReader *textfilereader = NULL ;
+    TextFileReader *textfilereader = nullptr ;
     TS_ASSERT_THROWS_NOTHING(
       textfilereader = new TextFileReader(test_file_name)) ;
     TS_ASSERT(textfilereader->read_line(line)) ;
diff --git a/owlps-positioner/tests/textfilewriter_test.hh b/owlps-positioner/tests/textfilewriter_test.hh
index 83af274..45855b1 100644
--- a/owlps-positioner/tests/textfilewriter_test.hh
+++ b/owlps-positioner/tests/textfilewriter_test.hh
@@ -48,7 +48,7 @@ public:
 
   void test_textfilewriter(void)
   {
-    TextFileWriter *textfilewriter = NULL ;
+    TextFileWriter *textfilewriter = nullptr ;
     TS_ASSERT_THROWS_NOTHING(
       textfilewriter = new TextFileWriter(test_file_name)) ;
     TS_ASSERT(textfilewriter->write_text("Hello\nWorld\n")) ;
diff --git a/owlps-positioner/tests/topologyreadercsv_test.hh b/owlps-positioner/tests/topologyreadercsv_test.hh
index 972e37f..75bfcba 100644
--- a/owlps-positioner/tests/topologyreadercsv_test.hh
+++ b/owlps-positioner/tests/topologyreadercsv_test.hh
@@ -73,11 +73,11 @@ public:
 
   void test_areas(void)
   {
-    Building *building1 = NULL ;
+    Building *building1 = nullptr ;
     TS_ASSERT_THROWS_NOTHING(
       building1 = const_cast<Building*>(
                     &Stock::get_building("My building"))) ;
-    Building *building2 = NULL ;
+    Building *building2 = nullptr ;
     TS_ASSERT_THROWS_NOTHING(
       building2 = const_cast<Building*>(
                     &Stock::get_building("Building #2"))) ;
@@ -107,11 +107,11 @@ public:
 
   void test_waypoints(void)
   {
-    Building *building1 = NULL ;
+    Building *building1 = nullptr ;
     TS_ASSERT_THROWS_NOTHING(
       building1 = const_cast<Building*>(
                     &Stock::get_building("My building"))) ;
-    Building *building2 = NULL ;
+    Building *building2 = nullptr ;
     TS_ASSERT_THROWS_NOTHING(
       building2 = const_cast<Building*>(
                     &Stock::get_building("Building #2"))) ;
diff --git a/owlps-positioner/tests/waypoint_test.hh b/owlps-positioner/tests/waypoint_test.hh
index 5a3f890..f430847 100644
--- a/owlps-positioner/tests/waypoint_test.hh
+++ b/owlps-positioner/tests/waypoint_test.hh
@@ -24,7 +24,7 @@ public:
   {
     // Default constructor
     Waypoint wp00 ;
-    Waypoint wp01(NULL, 0, 0, 0) ;
+    Waypoint wp01(nullptr, 0, 0, 0) ;
     TS_ASSERT_EQUALS(wp00, wp01) ;
 
     // Copy constructor
@@ -37,7 +37,7 @@ public:
     Point3D p0(5, 3, 8) ;
     Waypoint wp4(p0) ;
     TS_ASSERT_EQUALS(p0, wp4) ;
-    Waypoint wp5(NULL, p0) ;
+    Waypoint wp5(nullptr, p0) ;
     TS_ASSERT_EQUALS(wp4, wp5) ;
 
     // 3-float array constructor
@@ -76,12 +76,12 @@ public:
   void test_operators(void)
   {
     // ==
-    Waypoint wp1(NULL, 42, 21, 19) ;
-    Waypoint wp2(NULL, 42, 21, 19) ;
+    Waypoint wp1(nullptr, 42, 21, 19) ;
+    Waypoint wp2(nullptr, 42, 21, 19) ;
     TS_ASSERT_EQUALS(wp1, wp2) ;
 
     // !=
-    Waypoint wp3(NULL, 1, 4, 7) ;
+    Waypoint wp3(nullptr, 1, 4, 7) ;
     TS_ASSERT(wp1 != wp3) ;
 
     // =
diff --git a/owlps-positioner/trilaterationalgorithm.cc b/owlps-positioner/trilaterationalgorithm.cc
index 51afea7..157618a 100644
--- a/owlps-positioner/trilaterationalgorithm.cc
+++ b/owlps-positioner/trilaterationalgorithm.cc
@@ -26,7 +26,7 @@ using namespace std ;
 
 
 TrilaterationAlgorithm::TrilaterationAlgorithm():
-  request(NULL)
+  request(nullptr)
 {
   // Will be changed when other trilateration methods will be
   // implemented.
diff --git a/owlps-positioner/waypoint.cc b/owlps-positioner/waypoint.cc
index 97bd383..3584ce1 100644
--- a/owlps-positioner/waypoint.cc
+++ b/owlps-positioner/waypoint.cc
@@ -26,7 +26,7 @@ using namespace std ;
 
 /**
  * @param _b A pointer to the (first) Building to add to #buildings.
- * If it is NULL, #buildings will remain empty.
+ * If it is null, #buildings will remain empty.
  * @param _x X coordinate.
  * @param _y Y coordinate.
  * @param _z Z coordinate.
@@ -42,7 +42,7 @@ Waypoint::Waypoint(Building *const _b,
 
 /**
  * @param _b A pointer to the (first) Building to add to #buildings.
- * If it is NULL, #buildings will remain empty.
+ * If it is null, #buildings will remain empty.
  * @param p Coordinates of the Waypoint.
  */
 Waypoint::Waypoint(Building *const _b, const Point3D &p): Point3D(p)
diff --git a/owlps-positioner/waypoint.hh b/owlps-positioner/waypoint.hh
index 640d902..5b62620 100644
--- a/owlps-positioner/waypoint.hh
+++ b/owlps-positioner/waypoint.hh
@@ -37,7 +37,7 @@ protected:
   std::unordered_set<Building*> buildings ;
 
 public:
-  Waypoint(Building *const _b = NULL, const float _x = 0,
+  Waypoint(Building *const _b = nullptr, const float _x = 0,
            const float _y = 0, const float _z = 0) ;
 
   Waypoint(Building *const _b, const Point3D &p) ;
@@ -84,13 +84,13 @@ public:
 
 /**
  * @returns A pointer to the first Building associated with the Waypoint
- * (i.e. the first element of #buildings). If #buildings is empty, NULL
- * is returned.
+ * (i.e. the first element of #buildings). If #buildings is empty,
+ * nullptr is returned.
  */
 inline Building* Waypoint::get_1st_building() const
 {
   if (buildings.empty())
-    return NULL ;
+    return nullptr ;
   return *buildings.begin() ;
 }
 
@@ -107,8 +107,8 @@ Waypoint::get_buildings() const
 
 
 /**
- * @param _b A pointer to the Building to add. If it is
- * NULL, nothing will be done.
+ * @param _b A pointer to the Building to add. If it is null, nothing
+ * will be done.
  * The memory pointed by this pointer must not be deallocated before
  * the Waypoint destruction (do *not* pass a pointer to a local
  * variable!).