diff --git a/test/unitvectortest.cc b/test/unitvectortest.cc
index 0b1880fed85102f9b152ac65d9637031e33703fb..ded44a5f81a66cdaa0db9c1d4970c94b5b6d6ba9 100644
--- a/test/unitvectortest.cc
+++ b/test/unitvectortest.cc
@@ -82,6 +82,17 @@ FieldMatrix<double,worldDim,worldDim> getSecondDerivativeOfSecondArgumentFD(cons
     return ret2;
 }
 
+template <class TargetSpace, int worldDim>
+void testOrthonormalFrame(const TargetSpace& a)
+{
+    const size_t spaceDim = TargetSpace::dim;
+    FieldMatrix<double,spaceDim,worldDim> B = a.orthonormalFrame();
+
+    for (int i=0; i<spaceDim; i++)
+        for (int j=0; j<spaceDim; j++)
+            assert( std::fabs(B[i]*B[j] - (i==j)) < 1e-10 );
+}
+
 template <class TargetSpace, int dim>
 void testDerivativeOfSquaredDistance(const TargetSpace& a, const TargetSpace& b)
 {
@@ -291,10 +302,13 @@ void testUnitVector2d()
     // Set up elements of S^1
     for (int i=0; i<nTestPoints; i++) {
         
+        Dune::array<double,2> w0 = {testPoints[i][0], testPoints[i][1]};
+        UnitVector<2> v0(w0);
+
+        testOrthonormalFrame<UnitVector<2>, 2>(v0);
+        
         for (int j=0; j<nTestPoints; j++) {
             
-            Dune::array<double,2> w0 = {testPoints[i][0], testPoints[i][1]};
-            UnitVector<2> v0(w0);
             Dune::array<double,2> w1 = {testPoints[j][0], testPoints[j][1]};
             UnitVector<2> v1(w1);
         
@@ -319,10 +333,13 @@ void testUnitVector3d()
     // Set up elements of S^1
     for (int i=0; i<nTestPoints; i++) {
         
+        Dune::array<double,3> w0 = {testPoints[i][0], testPoints[i][1], testPoints[i][2]};
+        UnitVector<3> uv0(w0);
+
+        testOrthonormalFrame<UnitVector<3>, 3>(uv0);
+        
         for (int j=0; j<nTestPoints; j++) {
             
-            Dune::array<double,3> w0 = {testPoints[i][0], testPoints[i][1], testPoints[i][2]};
-            UnitVector<3> uv0(w0);
             Dune::array<double,3> w1 = {testPoints[j][0], testPoints[j][1], testPoints[j][2]};
             UnitVector<3> uv1(w1);