diff -ruN a/compat/getopt.c b/compat/getopt.c
--- a/compat/getopt.c	2025-09-10 00:44:17.560000000 +0000
+++ b/compat/getopt.c	2025-09-10 01:22:33.360000000 +0000
@@ -211,7 +211,7 @@
 /* Avoid depending on library functions or files
    whose names are inconsistent.  */
 
-char *getenv ();
+char *getenv (const char *);
 
 static char *
 my_index (str, chr)
diff -ruN a/compat/getopt.h b/compat/getopt.h
--- a/compat/getopt.h	2011-10-30 16:48:42.000000000 +0000
+++ b/compat/getopt.h	2025-09-10 01:21:26.450000000 +0000
@@ -105,7 +105,7 @@
    errors, only prototype getopt for the GNU C library.  */
 extern int getopt (int argc, char *const *argv, const char *shortopts);
 #else /* not __GNU_LIBRARY__ */
-extern int getopt ();
+extern int getopt(int, char * const [], const char *);
 #endif /* __GNU_LIBRARY__ */
 extern int getopt_long (int argc, char *const *argv, const char *shortopts,
 		        const struct option *longopts, int *longind);