diff --git a/src/BuildTiles/Parallel/server.cxx b/src/BuildTiles/Parallel/server.cxx
index 5914b9d6..28317087 100644
--- a/src/BuildTiles/Parallel/server.cxx
+++ b/src/BuildTiles/Parallel/server.cxx
@@ -29,7 +29,7 @@ SG_USING_STD( cout );
 SG_USING_STD( cerr );
 SG_USING_STD( endl );
 
-#if defined (sun) || defined (__CYGWIN__) || defined(sgi)
+#if defined (__sun) || defined (__CYGWIN__) || defined(sgi)
 #  define WAIT_ANY (pid_t)-1
 #endif