diff --git a/include/wx_pb.h b/include/wx_pb.h
index a23fb6d357..82bcb1756c 100644
--- a/include/wx_pb.h
+++ b/include/wx_pb.h
@@ -11,3 +11,4 @@
 
 #define HAVE_USLEEP 1
 #define HAVE_FCNTL  1
+#define SIZEOF_INT 4