diff -ruwN source/tparam.c source-new/tparam.c
--- source/tparam.c	2002-02-25 17:37:24.000000000 +0000
+++ source-new/tparam.c	2026-09-22 15:11:03.072524045 +0000
@@ -38,6 +38,10 @@
 #define bcopy(s, d, n) memcpy ((d), (s), (n))
 #endif
 
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
 #endif /* not emacs */
 
 #ifndef NULL