diff --git a/Wrapping/Tools/vtkWrapPython.c b/Wrapping/Tools/vtkWrapPython.c
index 5da3bc138236c0c958e243e317025908e237adc7..5ebd9548ddb70f5db963e4ff646d78e5e72cd7b3 100644
--- a/Wrapping/Tools/vtkWrapPython.c
+++ b/Wrapping/Tools/vtkWrapPython.c
@@ -385,6 +385,7 @@ int main(int argc, char *argv[])
           "#include \"vtkPythonArgs.h\"\n"
           "#include \"vtkPythonOverload.h\"\n"
           "#include \"vtkConfigure.h\"\n"
+          "#include <cstddef>\n"
           "#include <sstream>\n");
 
   /* vtkPythonCommand is needed to wrap vtkObject.h */