/* Unsigned type of `sizeof' something. */
-#ifndef _SIZE_T /* in case <sys/types.h> has defined it. */
+/* in case <sys/types.h> has defined it. */
+/* DECstation uses _SIZE_T_. */
+#if !defined (_SIZE_T) && !defined (_SIZE_T_)
#define _SIZE_T
typedef unsigned long size_t;
#endif /* _SIZE_T */