diff --git a/owlps-positioner/direction.cc b/owlps-positioner/direction.cc
index cf239df..b97e2dd 100644
--- a/owlps-positioner/direction.cc
+++ b/owlps-positioner/direction.cc
@@ -63,6 +63,12 @@ Direction& Direction::operator=(const char source)
 }
 
 
+Direction::operator bool() const
+{
+  return is_valid() ;
+}
+
+
 Direction::operator std::string() const
 {
   switch (direction)
diff --git a/owlps-positioner/direction.hh b/owlps-positioner/direction.hh
index 5dfb41b..bfa62f9 100644
--- a/owlps-positioner/direction.hh
+++ b/owlps-positioner/direction.hh
@@ -78,12 +78,6 @@ inline bool Direction::operator!=(const Direction &source) const
 }
 
 
-inline Direction::operator bool() const
-{
-  return is_valid() ;
-}
-
-
 inline Direction::operator int() const
 {
   return static_cast<int>(direction) ;