diff --git a/src/OpenFOAM/containers/Lists/ListOps/ListOps.C b/src/OpenFOAM/containers/Lists/ListOps/ListOps.C
index a9dcbe54191c30953f5c5174b471fc185401e2d5..7e756447baa15ded1ff054b7eaec476ab37ce5c7 100644
--- a/src/OpenFOAM/containers/Lists/ListOps/ListOps.C
+++ b/src/OpenFOAM/containers/Lists/ListOps/ListOps.C
@@ -160,7 +160,7 @@ void Foam::inplaceReorder
 }
 
 
-void Foam::ListOps::identity(labelList& map, label start)
+void Foam::ListOps::identity(labelUList& map, label start)
 {
     std::iota(map.begin(), map.end(), start);
 }
diff --git a/src/OpenFOAM/containers/Lists/ListOps/ListOps.H b/src/OpenFOAM/containers/Lists/ListOps/ListOps.H
index 70d14a7af3f34f02b0333b23b04d1c7c147191fa..da169dbf1419685bd41cde5896e697ed694fb2dd 100644
--- a/src/OpenFOAM/containers/Lists/ListOps/ListOps.H
+++ b/src/OpenFOAM/containers/Lists/ListOps/ListOps.H
@@ -586,7 +586,7 @@ struct greater
 
 //- Set identity map with (map[i] == i)
 //  Optionally with an alternative start index, so that (map[i] == i+start)
-void identity(labelList& map, label start=0);
+void identity(labelUList& map, label start=0);
 
 
 //- Find index of the first occurrence that satisfies the predicate.