diff --git a/mkvmuxer/mkvmuxer.cc b/mkvmuxer/mkvmuxer.cc
index 5926a15..499fbe6 100644
--- a/mkvmuxer/mkvmuxer.cc
+++ b/mkvmuxer/mkvmuxer.cc
@@ -2622,7 +2622,8 @@
 
 uint64_t Cluster::Size() const {
   const uint64_t element_size =
-      EbmlMasterElementSize(libwebm::kMkvCluster, 0xFFFFFFFFFFFFFFFFULL) +
+      EbmlMasterElementSize(static_cast<uint64_t>(libwebm::kMkvCluster),
+                            uint64_t{0xFFFFFFFFFFFFFFFFU}) +
       payload_size_;
   return element_size;
 }