diff --git a/src/d_net.cpp b/src/d_net.cpp
index 453a1ff322..2e8e9aca22 100644
--- a/src/d_net.cpp
+++ b/src/d_net.cpp
@@ -26,6 +26,7 @@
 //-----------------------------------------------------------------------------
 
 #include <stddef.h>
+#define __STDC_FORMAT_MACROS
 #include <inttypes.h>
 
 #include "version.h"