diff --git a/include/dgl/runtime/parallel_for.h b/include/dgl/runtime/parallel_for.h
index 85143de8e980..d4e9c3913a47 100644
--- a/include/dgl/runtime/parallel_for.h
+++ b/include/dgl/runtime/parallel_for.h
@@ -85,7 +85,7 @@ void parallel_for(
     auto chunk_size = divup((end - begin), num_threads);
     auto begin_tid = begin + tid * chunk_size;
     if (begin_tid < end) {
-      auto end_tid = std::min(end, chunk_size + begin_tid);
+      auto end_tid = std::min(end, static_cast<size_t>(chunk_size + begin_tid));
       try {
         f(begin_tid, end_tid);
       } catch (...) {