diff --git a/include/osg/Matrix b/include/osg/Matrix
index 85e600f5e..977b9df6a 100644
--- a/include/osg/Matrix
+++ b/include/osg/Matrix
@@ -17,17 +17,18 @@
 #include <osg/Matrixd>
 #include <osg/Matrixf>
 
+#define OSG_USE_DOUBLE_MATRICES 1
+
 namespace osg {
 
-
-// default to using floating Matrices - Matrixf 
-//    typedef Matrixf Matrix;
-//    typedef RefMatrixf RefMatrix;
-
-// // default to using double Matrices - Matrixd
+#ifdef OSG_USE_DOUBLE_MATRICES
     typedef Matrixd Matrix;
     typedef RefMatrixd RefMatrix;
+#else
+    typedef Matrixf Matrix;
+    typedef RefMatrixf RefMatrix;
 
+#endif
 
 } //namespace osg
 
diff --git a/include/osg/Matrixd b/include/osg/Matrixd
index f30ea4740..16d3e71d6 100644
--- a/include/osg/Matrixd
+++ b/include/osg/Matrixd
@@ -33,7 +33,7 @@ class SG_EXPORT Matrixd
 
     public:
     
-        typedef float value_type;
+        typedef double value_type;
 
         inline Matrixd() { makeIdentity(); }
         inline Matrixd( const Matrixd& mat) { set(mat.ptr()); }