diff --git a/vtkm/thirdparty/diy/vtkmdiy/include/vtkmdiy/resolve.hpp b/vtkm/thirdparty/diy/vtkmdiy/include/vtkmdiy/resolve.hpp
index dae88c6f83af4d52ff0ccd23b20e95c017a229ac..be322370875511ed7cfdec4c59be04127286b08f 100644
--- a/vtkm/thirdparty/diy/vtkmdiy/include/vtkmdiy/resolve.hpp
+++ b/vtkm/thirdparty/diy/vtkmdiy/include/vtkmdiy/resolve.hpp
@@ -20,7 +20,7 @@ record_local_gids(const diy::Master& master, diy::DynamicAssigner& assigner)
 {
     // figure out local ranks
     std::vector<std::tuple<int,int>> local_gids;
-    for (int i = 0; i < master.size(); ++i)
+    for (int i = 0; i < static_cast<int>(master.size()); ++i)
         local_gids.emplace_back(std::make_tuple(master.communicator().rank(), master.gid(i)));
 
     assigner.set_ranks(local_gids);
@@ -32,7 +32,7 @@ update_links(diy::Master& master, const diy::DynamicAssigner& assigner)
 {
     // figure out all the gids we need
     std::vector<int> nbr_gids;
-    for (int i = 0; i < master.size(); ++i)
+    for (int i = 0; i < static_cast<int>(master.size()); ++i)
     {
         auto* link = master.link(i);
         for (auto blockid : link->neighbors())
@@ -52,7 +52,7 @@ update_links(diy::Master& master, const diy::DynamicAssigner& assigner)
         gid_to_proc[nbr_gids[i]] = nbr_procs[i];
 
     // fix the procs in links
-    for (int i = 0; i < master.size(); ++i)
+    for (int i = 0; i < static_cast<int>(master.size()); ++i)
     {
         auto* link = master.link(i);
         for (auto& blockid : link->neighbors())