diff --git a/include/osg/Vec4d b/include/osg/Vec4d
index 0c4cb9596..12f8011a4 100644
--- a/include/osg/Vec4d
+++ b/include/osg/Vec4d
@@ -236,18 +236,27 @@ class Vec4d
             return( norm );
         }
 
-        friend inline std::ostream& operator << (std::ostream& output, const Vec4d& vec)
-        {
-        output << vec._v[0] << " "
-                   << vec._v[1] << " "
-                   << vec._v[2] << " "
-                   << vec._v[3];
-        return output;     // to enable cascading
-    }
-
 };    // end of class Vec4d
 
 
+// streaming operators
+
+inline std::ostream& operator << (std::ostream& output, const Vec4d& vec)
+{
+    output << vec._v[0] << " "
+           << vec._v[1] << " "
+           << vec._v[2] << " "
+           << vec._v[3];
+    return output;     // to enable cascading
+}
+
+inline std::istream& operator >> (std::istream& input, Vec4d& vec)
+{
+    input >> vec._v[0] >> vec._v[1] >> vec._v[2] >> vec._v[3];
+    return input;
+}
+
+
 /** Compute the dot product of a (Vec3,1.0) and a Vec4d. */
 inline Vec4d::value_type operator * (const Vec3d& lhs,const Vec4d& rhs)
 {