diff --git a/include/cli.h b/include/cli.h
index a01c8fc..262bf79 100644
--- a/include/cli.h
+++ b/include/cli.h
@@ -40,7 +40,7 @@ enum { CLI_OPT_ARG_TYPES };
 
 void cli_set_prog_name(const char *name);
 void cli_print_options(const struct option_descriptor *opts, size_t nb_opts,
-		t_arg_type_to_str to_str);
+		t_arg_type_to_str to_str) __attribute__((weak));
 
 const char *cli_arg_type_to_str(int type);