--- /dev/null
+Extended malloc attributes are available since gcc 11.
+--- whois/utils.h.orig 2023-10-08 22:58:33.000000000 +0200
++++ whois/utils.h 2023-10-21 17:56:23.225691505 +0200
+@@ -17,7 +17,11 @@
+ /* Portability macros */
+ #ifdef __GNUC__
+ # define NORETURN __attribute__((noreturn))
++# if __GNUC__ >= 11
+ # define MALLOC_FREE __attribute__((malloc(free)))
++# else
++# define MALLOC_FREE
++# endif
+ # define NONNULL __attribute__((returns_nonnull))
+ #else
+ # define NORETURN