diff --git a/helpers/self_update.py b/helpers/self_update.py
index 89b1386d6..326bbdaa3 100644
--- a/helpers/self_update.py
+++ b/helpers/self_update.py
@@ -3,6 +3,8 @@ from __future__ import annotations
 import os
 import re
 import subprocess
+import tempfile
+import time
 from datetime import UTC, datetime
 from pathlib import Path
 from typing import Any, Literal, TypedDict
@@ -20,11 +22,14 @@ BRANCH_OPTIONS = [
 SUPPORTED_BRANCHES = {option["value"] for option in BRANCH_OPTIONS}
 BACKUP_CONFLICT_POLICIES = {"rename", "overwrite", "fail"}
 MIN_SELECTOR_VERSION = (1, 0)
+REMOTE_BRANCH_TAG_CACHE_TTL_SECONDS = 60.0
 
 UPDATE_FILE_PATH = Path("/exe/a0-self-update.yaml")
 STATUS_FILE_PATH = Path("/exe/a0-self-update-status.yaml")
 LOG_FILE_PATH = Path("/exe/a0-self-update.log")
 
+_remote_branch_tag_cache: dict[str, tuple[float, set[str]]] = {}
+
 
 class PendingUpdateConfig(TypedDict):
     branch: Literal["main", "testing", "development"]
@@ -113,6 +118,10 @@ def get_repo_dir(repo_dir: str | Path | None = None) -> Path:
     return Path(__file__).resolve().parents[1]
 
 
+def _get_official_remote_url() -> str:
+    return f"https://github.com/{OFFICIAL_REPO_AUTHOR}/{OFFICIAL_REPO_NAME}.git"
+
+
 def _run_git(repo_dir: str | Path, *args: str) -> str:
     completed = subprocess.run(
         ["git", "-C", str(get_repo_dir(repo_dir)), *args],
@@ -192,7 +201,37 @@ def _get_branch_reference_names(branch: str) -> list[str]:
     return [f"origin/{normalized_branch}", normalized_branch]
 
 
-def _get_branch_merged_tags(
+def _get_remote_branch_merged_tags(branch: str) -> set[str]:
+    normalized_branch = branch.strip().lower()
+    if normalized_branch not in SUPPORTED_BRANCHES:
+        return set()
+
+    cached = _remote_branch_tag_cache.get(normalized_branch)
+    now = time.monotonic()
+    if cached and now - cached[0] <= REMOTE_BRANCH_TAG_CACHE_TTL_SECONDS:
+        return set(cached[1])
+
+    with tempfile.TemporaryDirectory(prefix="a0-self-update-tags-") as temp_dir:
+        repository = Path(temp_dir)
+        _run_git(repository, "init", "--bare")
+        _run_git(
+            repository,
+            "fetch",
+            "--quiet",
+            "--prune",
+            "--filter=blob:none",
+            "--tags",
+            _get_official_remote_url(),
+            f"refs/heads/{normalized_branch}:refs/remotes/origin/{normalized_branch}",
+        )
+        output = _run_git(repository, "tag", "--merged", f"refs/remotes/origin/{normalized_branch}")
+        merged_tags = {line.strip() for line in output.splitlines() if line.strip()}
+
+    _remote_branch_tag_cache[normalized_branch] = (now, merged_tags)
+    return set(merged_tags)
+
+
+def _get_local_branch_merged_tags(
     branch: str,
     repo_dir: str | Path | None = None,
 ) -> set[str]:
@@ -207,6 +246,19 @@ def _get_branch_merged_tags(
     return set()
 
 
+def _get_branch_merged_tags(
+    branch: str,
+    repo_dir: str | Path | None = None,
+) -> set[str]:
+    try:
+        remote_tags = _get_remote_branch_merged_tags(branch)
+        if remote_tags:
+            return remote_tags
+    except Exception:
+        pass
+    return _get_local_branch_merged_tags(branch, repo_dir=repo_dir)
+
+
 def _parse_selector_version(tag: str) -> tuple[int, int] | None:
     match = re.fullmatch(r"v(\d+)\.(\d+)", tag.strip())
     if not match:
diff --git a/tests/test_self_update_tag_filter.py b/tests/test_self_update_tag_filter.py
index 3387e3032..1897bfba3 100644
--- a/tests/test_self_update_tag_filter.py
+++ b/tests/test_self_update_tag_filter.py
@@ -36,6 +36,36 @@ def test_self_update_selector_tags_are_sorted_numerically():
     ]
 
 
+def test_self_update_branch_filter_prefers_remote_branch_tags(monkeypatch):
+    monkeypatch.setattr(
+        self_update.git,
+        "get_remote_releases",
+        lambda author, repo: types.SimpleNamespace(
+            error="",
+            releases=[
+                types.SimpleNamespace(tag="v1.2"),
+                types.SimpleNamespace(tag="v1.1"),
+                types.SimpleNamespace(tag="v1.0"),
+            ],
+        ),
+    )
+    monkeypatch.setattr(
+        self_update,
+        "_get_remote_branch_merged_tags",
+        lambda branch: {"v1.1", "v1.0"},
+    )
+    monkeypatch.setattr(
+        self_update,
+        "_get_local_branch_merged_tags",
+        lambda branch, repo_dir=None: set(),
+    )
+
+    tags, error = self_update.get_available_tags("development")
+
+    assert error == ""
+    assert tags == ["v1.1", "v1.0"]
+
+
 def test_self_update_frontend_filters_old_tag_suggestions():
     store_path = (
         PROJECT_ROOT