diff --git a/gateway/config.py b/gateway/config.py
index 94136291284..0591503938b 100644
--- a/gateway/config.py
+++ b/gateway/config.py
@@ -1062,6 +1062,12 @@ def load_gateway_config() -> GatewayConfig:
                             extra = {}
                             plat_data["extra"] = extra
                         extra[_telegram_extra_key] = telegram_cfg[_telegram_extra_key]
+                if _telegram_extra:
+                    _plat_data, _plat_extra = _ensure_platform_extra_dict(
+                        platforms_data, Platform.TELEGRAM.value
+                    )
+                    for _telegram_extra_key, _telegram_extra_value in _telegram_extra.items():
+                        _plat_extra.setdefault(_telegram_extra_key, _telegram_extra_value)
 
             whatsapp_cfg = yaml_cfg.get("whatsapp", {})
             if isinstance(whatsapp_cfg, dict):
diff --git a/tests/gateway/test_config.py b/tests/gateway/test_config.py
index fdd5e72f680..da7673011fe 100644
--- a/tests/gateway/test_config.py
+++ b/tests/gateway/test_config.py
@@ -551,6 +551,26 @@ class TestLoadGatewayConfig:
 
         assert config.platforms[Platform.TELEGRAM].extra["disable_link_previews"] is True
 
+    def test_bridges_telegram_extra_base_url_from_config_yaml(self, tmp_path, monkeypatch):
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        config_path = hermes_home / "config.yaml"
+        config_path.write_text(
+            "telegram:\n"
+            "  extra:\n"
+            "    base_url: https://custom-proxy.example.com/bot\n",
+            encoding="utf-8",
+        )
+
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+        config = load_gateway_config()
+
+        assert (
+            config.platforms[Platform.TELEGRAM].extra["base_url"]
+            == "https://custom-proxy.example.com/bot"
+        )
+
     def test_bridges_notice_delivery_from_config_yaml(self, tmp_path, monkeypatch):
         hermes_home = tmp_path / ".hermes"
         hermes_home.mkdir()