diff --git a/src/rotation.hh b/src/rotation.hh
index 980615545ee7190e8d0ebe1799541b0bcaa49f98..c0bb26c7a2685a581f22832db93ce61c2bbfcc26 100644
--- a/src/rotation.hh
+++ b/src/rotation.hh
@@ -34,6 +34,9 @@ class Rotation<3,T> : public Quaternion<T>
 
 public:
 
+    /** \brief The type used for coordinates */
+    typedef T ctype;
+
     /** \brief Member of the corresponding Lie algebra.  This really is a skew-symmetric matrix */
     typedef Dune::FieldVector<T,3> TangentVector;