diff --git a/src/include/port/win32ntdll.h b/src/include/port/win32ntdll.h
index 4d8808b3aaf..b29b06b91f9 100644
--- a/src/include/port/win32ntdll.h
+++ b/src/include/port/win32ntdll.h
@@ -11,6 +11,9 @@
  *-------------------------------------------------------------------------
  */
 
+#ifndef WIN32NTDLL_H
+#define WIN32NTDLL_H
+
 /*
  * Because this includes NT headers that normally conflict with Win32 headers,
  * any translation unit that includes it should #define UMDF_USING_NTSTATUS
@@ -25,3 +28,5 @@ typedef NTSTATUS (__stdcall *RtlGetLastNtStatus_t) (void);
 extern RtlGetLastNtStatus_t pg_RtlGetLastNtStatus;
 
 extern int	initialize_ntdll(void);
+
+#endif							/* WIN32NTDLL_H */
diff --git a/src/tools/pginclude/cpluspluscheck b/src/tools/pginclude/cpluspluscheck
index a5132cbadf2..eadb6fa105a 100755
--- a/src/tools/pginclude/cpluspluscheck
+++ b/src/tools/pginclude/cpluspluscheck
@@ -75,6 +75,7 @@ do
 	test "$f" = src/include/port/win32/sys/socket.h && continue
 	test "$f" = src/include/port/win32_msvc/dirent.h && continue
 	test "$f" = src/include/port/win32_msvc/utime.h && continue
+	test "$f" = src/include/port/win32ntdll.h && continue
 	test "$f" = src/port/pthread-win32.h && continue
 
 	# Likewise, these files are platform-specific, and the one
diff --git a/src/tools/pginclude/headerscheck b/src/tools/pginclude/headerscheck
index 9442db2d2ea..10c42f6e801 100755
--- a/src/tools/pginclude/headerscheck
+++ b/src/tools/pginclude/headerscheck
@@ -71,6 +71,7 @@ do
 	test "$f" = src/include/port/win32/sys/socket.h && continue
 	test "$f" = src/include/port/win32_msvc/dirent.h && continue
 	test "$f" = src/include/port/win32_msvc/utime.h && continue
+	test "$f" = src/include/port/win32ntdll.h && continue
 	test "$f" = src/port/pthread-win32.h && continue
 
 	# Likewise, these files are platform-specific, and the one