diff --git a/src/os_unix.h b/src/os_unix.h
index 0dd75cf..4504cce 100644
--- a/src/os_unix.h
+++ b/src/os_unix.h
@@ -75,13 +75,7 @@
 #endif
 
 #ifndef __ARGS
-    /* The AIX VisualAge cc compiler defines __EXTENDED__ instead of __STDC__
-     * because it includes pre-ansi features. */
-# if defined(__STDC__) || defined(__GNUC__) || defined(__EXTENDED__)
-#  define __ARGS(x) x
-# else
-#  define __ARGS(x) ()
-# endif
+# define __ARGS(x) x
 #endif
 
 /* always use unlink() to remove files */
@@ -181,10 +175,6 @@
 # include <pwd.h>
 #endif
 
-#ifdef __COHERENT__
-# undef __ARGS
-#endif
-
 #if (defined(HAVE_SYS_RESOURCE_H) && defined(HAVE_GETRLIMIT)) \
 	|| (defined(HAVE_SYS_SYSINFO_H) && defined(HAVE_SYSINFO)) \
 	|| defined(HAVE_SYSCTL) || defined(HAVE_SYSCONF)