--- enscript-1.6.6-origin/compat/getopt.c
+++ enscript-1.6.6/compat/getopt.c
@@ -111,6 +111,7 @@
    they can distinguish the relative order of options and other arguments.  */
 
 #include "getopt.h"
+#include <string.h>
 
 /* For communication from `getopt' to the caller.
    When `getopt' finds an option that takes an argument,