diff --git a/src/OpenFOAM/containers/Lists/ListOps/ListOps.H b/src/OpenFOAM/containers/Lists/ListOps/ListOps.H
index 7de9239d04deed112a68f7ddf745c5d1d933133c..1504fb4d78363167fd2f4e934270702728afc71d 100644
--- a/src/OpenFOAM/containers/Lists/ListOps/ListOps.H
+++ b/src/OpenFOAM/containers/Lists/ListOps/ListOps.H
@@ -73,7 +73,7 @@ void inplaceReorder(const UList<label>& oldToNew, ListType&);
 template<class Container>
 void inplaceMapValue(const UList<label>& oldToNew, Container&);
 
-//- Recreate with mapped keys. Remove elements with negative key.
+//- Recreate with mapped keys. Do not map elements with negative key.
 template<class Container>
 void inplaceMapKey(const UList<label>& oldToNew, Container&);
 
diff --git a/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C b/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C
index f2178ee38df53e583476328496325f068ef8fc34..dd8536eec9b9f1466c518e2069c4a96b489cdc80 100644
--- a/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C
+++ b/src/OpenFOAM/containers/Lists/ListOps/ListOpsTemplates.C
@@ -147,7 +147,7 @@ void Foam::inplaceMapKey
     Container& lst
 )
 {
-    Container newLst(lst);
+    Container newLst(lst.size());
 
     for
     (