diff --git a/general/hash.hpp b/general/hash.hpp
index 86d987d80..11b16bc7b 100644
--- a/general/hash.hpp
+++ b/general/hash.hpp
@@ -16,6 +16,7 @@
 #include "array.hpp"
 #include "globals.hpp"
 #include <type_traits>
+#include <cstdint> // uintXX_t

 namespace mfem
 {
diff --git a/general/mem_manager.cpp b/general/mem_manager.cpp
index 1261e7dd3..7fe34e01b 100644
--- a/general/mem_manager.cpp
+++ b/general/mem_manager.cpp
@@ -16,6 +16,7 @@
 #include <cstring> // std::memcpy, std::memcmp
 #include <unordered_map>
 #include <algorithm> // std::max
+#include <cstdint>// uintptr_t

 // Uncomment to try _WIN32 platform
 //#define _WIN32
diff --git a/mesh/vtk.hpp b/mesh/vtk.hpp
index a59bed275..38bdad7bc 100644
--- a/mesh/vtk.hpp
+++ b/mesh/vtk.hpp
@@ -12,6 +12,7 @@
 #ifndef MFEM_VTK
 #define MFEM_VTK

+#include <cstdint> // uintXX_t
 #include "../fem/geom.hpp"
 #include "../general/binaryio.hpp"