struct expire_reflog_cb {
        FILE *newlog;
-       const char *ref;
-       struct commit *ref_commit;
+       enum {
+               UE_NORMAL,
+               UE_ALWAYS,
+               UE_HEAD
+       } unreachable_expire_kind;
        struct commit_list *mark_list;
        unsigned long mark_limit;
        struct cmd_reflog_expire_cb *cmd;
                goto prune;
 
        if (timestamp < cb->cmd->expire_unreachable) {
-               if (!cb->ref_commit)
+               if (cb->unreachable_expire_kind == UE_ALWAYS)
                        goto prune;
                if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
                        goto prune;
                printf("keep %s", message);
        return 0;
  prune:
-       if (!cb->newlog || cb->cmd->verbose)
-               printf("%sprune %s", cb->newlog ? "" : "would ", message);
+       if (!cb->newlog)
+               printf("would prune %s", message);
+       else if (cb->cmd->verbose)
+               printf("prune %s", message);
+       return 0;
+}
+
+static int push_tip_to_list(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
+{
+       struct commit_list **list = cb_data;
+       struct commit *tip_commit;
+       if (flags & REF_ISSYMREF)
+               return 0;
+       tip_commit = lookup_commit_reference_gently(sha1, 1);
+       if (!tip_commit)
+               return 0;
+       commit_list_insert(tip_commit, list);
        return 0;
 }
 
        struct expire_reflog_cb cb;
        struct ref_lock *lock;
        char *log_file, *newlog_path = NULL;
+       struct commit *tip_commit;
+       struct commit_list *tips;
        int status = 0;
 
        memset(&cb, 0, sizeof(cb));
                cb.newlog = fopen(newlog_path, "w");
        }
 
-       cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
-       cb.ref = ref;
        cb.cmd = cmd;
-       if (cb.ref_commit) {
-               cb.mark_list = NULL;
-               commit_list_insert(cb.ref_commit, &cb.mark_list);
+
+       if (!cmd->expire_unreachable || !strcmp(ref, "HEAD")) {
+               tip_commit = NULL;
+               cb.unreachable_expire_kind = UE_HEAD;
+       } else {
+               tip_commit = lookup_commit_reference_gently(sha1, 1);
+               if (!tip_commit)
+                       cb.unreachable_expire_kind = UE_ALWAYS;
+               else
+                       cb.unreachable_expire_kind = UE_NORMAL;
+       }
+
+       if (cmd->expire_unreachable <= cmd->expire_total)
+               cb.unreachable_expire_kind = UE_ALWAYS;
+
+       cb.mark_list = NULL;
+       tips = NULL;
+       if (cb.unreachable_expire_kind != UE_ALWAYS) {
+               if (cb.unreachable_expire_kind == UE_HEAD) {
+                       struct commit_list *elem;
+                       for_each_ref(push_tip_to_list, &tips);
+                       for (elem = tips; elem; elem = elem->next)
+                               commit_list_insert(elem->item, &cb.mark_list);
+               } else {
+                       commit_list_insert(tip_commit, &cb.mark_list);
+               }
                cb.mark_limit = cmd->expire_total;
                mark_reachable(&cb);
        }
+
        for_each_reflog_ent(ref, expire_reflog_ent, &cb);
-       if (cb.ref_commit)
-               clear_commit_marks(cb.ref_commit, REACHABLE);
+
+       if (cb.unreachable_expire_kind != UE_ALWAYS) {
+               if (cb.unreachable_expire_kind == UE_HEAD) {
+                       struct commit_list *elem;
+                       for (elem = tips; elem; elem = elem->next)
+                               clear_commit_marks(tip_commit, REACHABLE);
+                       free_commit_list(tips);
+               } else {
+                       clear_commit_marks(tip_commit, REACHABLE);
+               }
+       }
  finish:
        if (cb.newlog) {
                if (fclose(cb.newlog)) {
                init_revisions(&cb.revs, prefix);
                if (cb.verbose)
                        printf("Marking reachable objects...");
-               mark_reachable_objects(&cb.revs, 0);
+               mark_reachable_objects(&cb.revs, 0, NULL);
                if (cb.verbose)
                        putchar('\n');
        }
        if (!strcmp(argv[1], "delete"))
                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 
-       /* Not a recognized reflog command..*/
-       usage(reflog_usage);
+       return cmd_log_reflog(argc, argv, prefix);
 }