diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index b75b01d..c0592c9 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -90,7 +90,7 @@
   fclose(file);
 }
 
-#ifdef __sun__
+#if defined(_sun__)
 int daemon(int nochdir, int noclose) {
   int fd;