diff --git a/dune/perftool/sumfact/horizontaladd.hh b/dune/perftool/sumfact/horizontaladd.hh
index 153ed111d0f665d44bdc4acca913132c03caea46..db7634f0e5507214318dabb719240ff3674808ed 100644
--- a/dune/perftool/sumfact/horizontaladd.hh
+++ b/dune/perftool/sumfact/horizontaladd.hh
@@ -5,13 +5,13 @@
 
 
 template<class V>
-base_floatingpoint<V>::value horizontal_add_lower(const V& x)
+typename base_floatingpoint<V>::value horizontal_add_lower(const V& x)
 {
   return horizontal_add(x.get_low());
 }
 
 template<class V>
-base_floatingpoint<V>::value horizontal_add_upper(const V& x)
+typename base_floatingpoint<V>::value horizontal_add_upper(const V& x)
 {
   return horizontal_add(x.get_high());
 }