diff --git a/GraphicsView/include/CGAL/Qt/quaternion.h b/GraphicsView/include/CGAL/Qt/quaternion.h
index 279ffbb39d5..7a6db9af3a1 100644
--- a/GraphicsView/include/CGAL/Qt/quaternion.h
+++ b/GraphicsView/include/CGAL/Qt/quaternion.h
@@ -333,8 +333,8 @@ private:
   qreal q[4];
 };
 
+std::ostream &operator<<(std::ostream &o, const Quaternion &);
+
 }} // namespace CGAL::qglviewer
 
-std::ostream &operator<<(std::ostream &o, const CGAL::qglviewer::Quaternion &);
-
 #endif // QGLVIEWER_QUATERNION_H
diff --git a/GraphicsView/include/CGAL/Qt/quaternion_impl.h b/GraphicsView/include/CGAL/Qt/quaternion_impl.h
index 616ef35137f..e92eed00c3f 100644
--- a/GraphicsView/include/CGAL/Qt/quaternion_impl.h
+++ b/GraphicsView/include/CGAL/Qt/quaternion_impl.h
@@ -551,10 +551,10 @@ Quaternion Quaternion::randomQuaternion() {
   qreal t2 = 2.0 * CGAL_PI * (rand() / (qreal)RAND_MAX);
   return Quaternion(sin(t1) * r1, cos(t1) * r1, sin(t2) * r2, cos(t2) * r2);
 }
-  
-}} // namespace CGAL::qglviewer
 
 CGAL_INLINE_FUNCTION
-std::ostream &operator<<(std::ostream &o, const CGAL::qglviewer::Quaternion &Q) {
+std::ostream &operator<<(std::ostream &o, const Quaternion &Q) {
   return o << Q[0] << '\t' << Q[1] << '\t' << Q[2] << '\t' << Q[3];
 }
+
+}} // namespace CGAL::qglviewer
diff --git a/GraphicsView/include/CGAL/Qt/vec.h b/GraphicsView/include/CGAL/Qt/vec.h
index 0a6e2e2e95b..fcc9829dba3 100644
--- a/GraphicsView/include/CGAL/Qt/vec.h
+++ b/GraphicsView/include/CGAL/Qt/vec.h
@@ -361,8 +361,8 @@ cout << "Position=" << pos << endl;
 #endif
 };
 
+std::ostream &operator<<(std::ostream &o, const Vec &);
+
 }} // namespace CGAL::qglviewer
 
-std::ostream &operator<<(std::ostream &o, const CGAL::qglviewer::Vec &);
-
 #endif // QGLVIEWER_VEC_H
diff --git a/GraphicsView/include/CGAL/Qt/vec_impl.h b/GraphicsView/include/CGAL/Qt/vec_impl.h
index b7b317f3031..865ef09d85d 100644
--- a/GraphicsView/include/CGAL/Qt/vec_impl.h
+++ b/GraphicsView/include/CGAL/Qt/vec_impl.h
@@ -174,9 +174,9 @@ void Vec::initFromDOMElement(const QDomElement &element) {
   *this = v;
 }
 
-}} // namespace CGAL::qglviewer
-
 CGAL_INLINE_FUNCTION
-std::ostream &operator<<(std::ostream &o, const CGAL::qglviewer::Vec &v) {
+std::ostream &operator<<(std::ostream &o, const Vec &v) {
   return o << v.x << '\t' << v.y << '\t' << v.z;
-}
+}  
+
+}} // namespace CGAL::qglviewer