diff --git a/src/roddifference.hh b/src/roddifference.hh
index 0bb03b611b34b09cd553716f0a1376b7a2bb0c13..eac08f727828611852bbeb50ca75ec981d182b3d 100644
--- a/src/roddifference.hh
+++ b/src/roddifference.hh
@@ -1,6 +1,8 @@
 #ifndef ROD_DIFFERENCE_HH
 #define ROD_DIFFERENCE_HH
 
+#include "rigidbodymotion.hh"
+
 Dune::BlockVector<Dune::FieldVector<double,6> > computeRodDifference(const std::vector<RigidBodyMotion<3> >& a,
                                                                      const std::vector<RigidBodyMotion<3> >& b)
 {