int cmd_commit(int argc, const char **argv, const char *prefix)
 {
+       const char *argv_gc_auto[] = {"gc", "--auto", NULL};
        static struct wt_status s;
        static struct option builtin_commit_options[] = {
                OPT__QUIET(&quiet, N_("suppress summary after successful commit")),
                     "not exceeded, and then \"git reset HEAD\" to recover."));
 
        rerere(0);
+       run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
        run_commit_hook(use_editor, get_index_file(), "post-commit", NULL);
        if (amend && !no_post_rewrite) {
                commit_post_rewrite(current_head, &oid);