diff --git a/owlps-positioner/direction.hh b/owlps-positioner/direction.hh
index 870bd4b..6f98733 100644
--- a/owlps-positioner/direction.hh
+++ b/owlps-positioner/direction.hh
@@ -32,7 +32,7 @@ public:
   enum {north = 1, east, south, west} ;
 
   Direction(void): direction(0) {}
-  Direction(const uint_fast8_t source) ;
+  explicit Direction(const uint_fast8_t source);
   Direction(const Direction &source): direction(source.direction) {}
 
   /** @name Accessors */
diff --git a/owlps-positioner/inputudpsocket.cc b/owlps-positioner/inputudpsocket.cc
index 5bbf44e..dfa94c5 100644
--- a/owlps-positioner/inputudpsocket.cc
+++ b/owlps-positioner/inputudpsocket.cc
@@ -228,7 +228,7 @@ bool InputUDPSocket::fill_current_request()
 
   // Calibration request?
   fill_calibration_request_data(
-    mac_mobile, position, request.direction, request.type) ;
+    mac_mobile, position, Direction(request.direction), request.type);
 
   return true ;
 }
diff --git a/owlps-positioner/timestamp.cc b/owlps-positioner/timestamp.cc
index ec6717e..653db5b 100644
--- a/owlps-positioner/timestamp.cc
+++ b/owlps-positioner/timestamp.cc
@@ -152,7 +152,7 @@ Timestamp Timestamp::elapsed(const Timestamp &source) const
   d2 = source,
   elapsed ;
   owl_time_elapsed(&d1, &d2, &elapsed) ;
-  return elapsed ;
+  return Timestamp(elapsed);
 }
 
 
diff --git a/owlps-positioner/timestamp.hh b/owlps-positioner/timestamp.hh
index 2199683..7db11ef 100644
--- a/owlps-positioner/timestamp.hh
+++ b/owlps-positioner/timestamp.hh
@@ -63,7 +63,7 @@ protected:
 public:
   Timestamp(void) ;
   explicit Timestamp(const struct timespec &source);
-  Timestamp(const owl_timestamp &source) ;
+  explicit Timestamp(const owl_timestamp &source);
   Timestamp(const uint_fast32_t source_s, const uint_fast32_t source_ns) ;
   /// Constructs a Timsestamp from a value in milliseconds (deprecated)
   explicit Timestamp(const uint64_t source);