Index: /trunk/src/VBox/NetworkServices/NAT/VBoxNetLwipNAT.cpp
===================================================================
--- /trunk/src/VBox/NetworkServices/NAT/VBoxNetLwipNAT.cpp	(revision 50493)
+++ /trunk/src/VBox/NetworkServices/NAT/VBoxNetLwipNAT.cpp	(revision 50494)
@@ -15,4 +15,7 @@
  * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
  */
+
+/* Must be included before winutils.h (lwip/def.h), otherwise Windows build breaks. */
+#include <iprt/cpp/mem.h>
 
 #include "winutils.h"
@@ -49,5 +52,4 @@
 #include <iprt/file.h>
 #include <iprt/semaphore.h>
-#include <iprt/cpp/mem.h>
 #include <iprt/cpp/utils.h>
 #define LOG_GROUP LOG_GROUP_NAT_SERVICE