diff --git a/IO/Image/vtkSEPReader.h b/IO/Image/vtkSEPReader.h
--- a/IO/Image/vtkSEPReader.h
+++ b/IO/Image/vtkSEPReader.h
@@ -25,8 +25,9 @@
 #include "vtkImageAlgorithm.h"
 #include "vtkNew.h" // for ivars
 
-#include <array>  // for std::array
-#include <string> // for std::string
+#include <array>   // for std::array
+#include <cstdint> // for std::uint8_t and std::uint32_t
+#include <string>  // for std::string
 
 namespace details
 {
diff --git a/IO/PIO/PIOData.h b/IO/PIO/PIOData.h
--- a/IO/PIO/PIOData.h
+++ b/IO/PIO/PIOData.h
@@ -1,6 +1,7 @@
 #if !defined(_PIODATA_H)
 #define _PIODATA_H
 
+#include <cstdint>
 #include <fstream>
 #include <iostream>
 #include <list>
diff --git a/Rendering/Matplotlib/vtkMatplotlibMathTextUtilities.h b/Rendering/Matplotlib/vtkMatplotlibMathTextUtilities.h
--- a/Rendering/Matplotlib/vtkMatplotlibMathTextUtilities.h
+++ b/Rendering/Matplotlib/vtkMatplotlibMathTextUtilities.h
@@ -49,7 +49,8 @@
 #include "vtkMathTextUtilities.h"
 #include "vtkRenderingMatplotlibModule.h" // For export macro
 
-#include <vector> // for std::vector
+#include <cstdint> // for std::uint64_t
+#include <vector>  // for std::vector
 
 struct _object;
 typedef struct _object PyObject;
diff --git a/ThirdParty/libproj/vtklibproj/src/proj_json_streaming_writer.hpp b/ThirdParty/libproj/vtklibproj/src/proj_json_streaming_writer.hpp
--- a/ThirdParty/libproj/vtklibproj/src/proj_json_streaming_writer.hpp
+++ b/ThirdParty/libproj/vtklibproj/src/proj_json_streaming_writer.hpp
@@ -33,6 +33,7 @@
 
 #include <vector>
 #include <string>
+#include <cstdint>
 
 #define CPL_DLL