Index: /trunk/include/iprt/cdefs.h
===================================================================
--- /trunk/include/iprt/cdefs.h	(revision 58789)
+++ /trunk/include/iprt/cdefs.h	(revision 58790)
@@ -983,5 +983,5 @@
  *          the linux kernel and potentially elsewhere (3rd party).
  */
-#ifdef _MSC_VER
+#if defined(_MSC_VER) || defined(__WATCOMC__)
 # define RTCALL                 __cdecl
 #elif defined(RT_OS_OS2)