diff --git a/repos/base/include/base/capability.h b/repos/base/include/base/capability.h
index d47fc4dd6..8f2837506 100644
--- a/repos/base/include/base/capability.h
+++ b/repos/base/include/base/capability.h
@@ -159,7 +159,7 @@ class Genode::Capability : public Untyped_capability
 		Capability() { }
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call() const
 		{
 			Meta::Empty e;
@@ -167,7 +167,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1) const
 		{
 			Meta::Empty e;
@@ -176,7 +176,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1, typename Arg<IF, 1>::Type v2) const
 		{
 			Meta::Empty e;
@@ -185,7 +185,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1, typename Arg<IF, 1>::Type v2,
 		     typename Arg<IF, 2>::Type v3) const
 		{
@@ -195,7 +195,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1, typename Arg<IF, 1>::Type v2,
 		     typename Arg<IF, 2>::Type v3, typename Arg<IF, 3>::Type v4) const
 		{
@@ -205,7 +205,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1, typename Arg<IF, 1>::Type v2,
 		     typename Arg<IF, 2>::Type v3, typename Arg<IF, 3>::Type v4,
 		     typename Arg<IF, 4>::Type v5) const
@@ -216,7 +216,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1, typename Arg<IF, 1>::Type v2,
 		     typename Arg<IF, 2>::Type v3, typename Arg<IF, 3>::Type v4,
 		     typename Arg<IF, 4>::Type v5, typename Arg<IF, 5>::Type v6) const
@@ -227,7 +227,7 @@ class Genode::Capability : public Untyped_capability
 		}
 
 		template <typename IF>
-		typename Trait::Call_return<typename IF::Ret_type>::Type
+		typename IF::Ret_type
 		call(typename Arg<IF, 0>::Type v1, typename Arg<IF, 1>::Type v2,
 		     typename Arg<IF, 2>::Type v3, typename Arg<IF, 3>::Type v4,
 		     typename Arg<IF, 4>::Type v5, typename Arg<IF, 5>::Type v6,