diff --git a/src/lib/meta/trait.hpp b/src/lib/meta/trait.hpp
index 3ee151a81..49e0ebd76 100644
--- a/src/lib/meta/trait.hpp
+++ b/src/lib/meta/trait.hpp
@@ -77,6 +77,10 @@ namespace lib{
   
   namespace hash {
     class LuidH;
+  }
+  namespace time {
+    class TimeValue;
+    class Duration;
 }}
 namespace proc {
 namespace mobject{
@@ -385,6 +389,9 @@ namespace meta {
   
   TRAIT_IS_NARROWING (double, float)
   
+  TRAIT_IS_NARROWING (double, lib::time::TimeValue)
+  TRAIT_IS_NARROWING (double, lib::time::Duration)
+  
 #undef TRAIT_IS_NARROWING
   
   
diff --git a/tests/12metaprogramming.tests b/tests/12metaprogramming.tests
index 5effe5d75..e7d6f59f7 100644
--- a/tests/12metaprogramming.tests
+++ b/tests/12metaprogramming.tests
@@ -576,7 +576,7 @@ TEST "tuple initialisation from GenNode" TupleRecordInit_test <<END
 out: Rec...GenNode.+DataCap.«string».lalü, GenNode.+DataCap.«int».42
 out: Rec...GenNode.+DataCap.«string».lalü, GenNode.+DataCap.«string».lala, GenNode.+DataCap.«int».12, GenNode.+DataCap.«int».34, GenNode.+DataCap.«double».5.6, GenNode.+DataCap.«Time».0:09:08.007
 out-lit: «tuple<string, int>»──(lalü,42)
-out-lit: «tuple<idi::EntryID<long>, string, int, long, double, TimeVar>»──(ID<long>-lal,lala,12,34,5.6,548s7ms)
+out-lit: «tuple<idi::EntryID<long>, string, int, long, double, Duration>»──(ID<long>-lal,lala,12,34,5.6,≺548s7ms≻)
 return: 0
 END
 
diff --git a/tests/library/meta/tuple-record-init-test.cpp b/tests/library/meta/tuple-record-init-test.cpp
index 0020ed16e..6138cb0a3 100644
--- a/tests/library/meta/tuple-record-init-test.cpp
+++ b/tests/library/meta/tuple-record-init-test.cpp
@@ -42,7 +42,7 @@ using lib::diff::GenNode;
 using lib::meta::Types;
 using lib::meta::Tuple;
 using lib::meta::buildTuple;
-using lib::time::TimeVar;
+using lib::time::Duration;
 using lib::time::Time;
 using lib::hash::LuidH;
 
@@ -93,7 +93,7 @@ namespace test {
       show_simpleUsage()
         {
           using NiceTypes = Types<string, int>;
-          using UgglyTypes = Types<EntryID<long>, string, int, int64_t, double, TimeVar>;
+          using UgglyTypes = Types<EntryID<long>, string, int, int64_t, double, Duration>; // various conversions and an immutable type (Duration)
           
           Rec args = MakeRec().scope("lalü", 42);
           Rec urgs = MakeRec().scope("lalü", "lala", 12, 34, 5.6, Time(7,8,9));