diff --git a/libuavcan/include/uavcan/util/multiset.hpp b/libuavcan/include/uavcan/util/multiset.hpp
index 90e4bf3d6c..c1a99d31ea 100644
--- a/libuavcan/include/uavcan/util/multiset.hpp
+++ b/libuavcan/include/uavcan/util/multiset.hpp
@@ -171,9 +171,9 @@ private:
     template<typename Operator>
     struct OperatorToFalsePredicateAdapter : ::uavcan::Noncopyable
     {
-        const typename ParameterType<Operator>::Type oper;
+        Operator oper;
 
-        OperatorToFalsePredicateAdapter(typename ParameterType<Operator>::Type o)
+        OperatorToFalsePredicateAdapter(Operator o)
             : oper(o)
         { }