diff --git a/vidix/pci.c b/vidix/pci.c
index 2b85b86a71..7ccedb9adb 100644
--- a/vidix/pci.c
+++ b/vidix/pci.c
@@ -56,6 +56,7 @@
 #include <string.h>
 #include <stdio.h>
 #ifdef __unix__
+#define __USE_UNIX98
 #include <unistd.h>
 #endif
 #include "AsmMacros.h"