diff --git a/dune/contact/assemblers/dualmortarcouplinghierarchy.hh b/dune/contact/assemblers/dualmortarcouplinghierarchy.hh
index 7de21b9a5620a5c02dc26a7cbfc0942cd4e3c381..3850497555fe416b1ddb5e222867d06c2ec94154 100755
--- a/dune/contact/assemblers/dualmortarcouplinghierarchy.hh
+++ b/dune/contact/assemblers/dualmortarcouplinghierarchy.hh
@@ -13,6 +13,7 @@
 #include <dune/istl/bvector.hh>
 
 #include <dune/fufem/boundarypatch.hh>
+#include <dune/fufem/boundarypatchprolongator.hh>
 #include <dune/fufem/dgindexset.hh>
 
 #include <dune/grid-glue/merging/merger.hh>