diff --git a/EvoScientist/config/settings.py b/EvoScientist/config/settings.py
index bc8d9b5..979a8f6 100644
--- a/EvoScientist/config/settings.py
+++ b/EvoScientist/config/settings.py
@@ -334,7 +334,9 @@ class EvoScientistConfig:
     openrouter_anthropic_prompt_cache: bool = True
     # OpenRouter app attribution (issue #339). Sent only for the openrouter
     # provider; identifies EvoScientist in OpenRouter's app rankings/analytics.
-    # Override (e.g. a private fork) via these fields or their env vars.
+    # Override (e.g. a private fork) via these fields or their env vars. A custom
+    # title only takes effect together with a custom referer: OpenRouter keys app
+    # pages by referer, so a lone title would rename the shared EvoScientist page.
     # Defaults live in the module constants above (also imported by llm/models.py).
     openrouter_http_referer: str = OPENROUTER_DEFAULT_HTTP_REFERER
     openrouter_app_title: str = OPENROUTER_DEFAULT_APP_TITLE
diff --git a/EvoScientist/llm/models.py b/EvoScientist/llm/models.py
index 89c3758..df13d14 100644
--- a/EvoScientist/llm/models.py
+++ b/EvoScientist/llm/models.py
@@ -501,6 +501,11 @@ def get_chat_model(
             os.environ.get("EVOSCIENTIST_OPENROUTER_APP_TITLE", "").strip()
             or OPENROUTER_DEFAULT_APP_TITLE,
         )
+        # OpenRouter keys app pages by HTTP-Referer and X-Title only renames that
+        # page, so a custom title on the default referer would rename the shared
+        # EvoScientist page for everyone. Honor it only with a custom referer.
+        if kwargs["app_url"] == OPENROUTER_DEFAULT_HTTP_REFERER:
+            kwargs["app_title"] = OPENROUTER_DEFAULT_APP_TITLE
         # app_categories must be a list[str] (langchain-openrouter joins it into
         # the X-OpenRouter-Categories header); split the comma-separated config
         # value and drop blanks so a stray comma/space can't emit an empty one.
diff --git a/tests/test_llm.py b/tests/test_llm.py
index 78298a3..d74a5a1 100644
--- a/tests/test_llm.py
+++ b/tests/test_llm.py
@@ -1,5 +1,6 @@
 """Tests for EvoScientist LLM module."""
 
+import warnings
 from unittest.mock import patch
 
 import pytest
@@ -864,6 +865,34 @@ class TestThirdPartyRouting:
         # An explicit list is preserved verbatim, not re-split.
         assert call_kwargs["app_categories"] == ["only-this"]
 
+    @pytest.mark.parametrize("source", ["env", "kwarg"])
+    @patch("EvoScientist.llm.models.init_chat_model")
+    def test_openrouter_title_override_without_referer_falls_back_silently(
+        self, mock_init, monkeypatch, source
+    ):
+        """OpenRouter keys app pages by HTTP-Referer, so a custom title on the
+        default referer would rename the shared EvoScientist page. It is
+        replaced by the default title, without any user-facing warning,
+        whether the title came from the env (config) or an explicit kwarg."""
+        mock_init.return_value = "mock_model"
+        monkeypatch.setenv("OPENROUTER_API_KEY", "or-key")
+        for _env in self._APP_ATTR_ENV:
+            monkeypatch.delenv(_env, raising=False)
+        extra = {}
+        if source == "env":
+            monkeypatch.setenv("EVOSCIENTIST_OPENROUTER_APP_TITLE", "Acme")
+        else:
+            extra["app_title"] = "Acme"
+
+        with warnings.catch_warnings(record=True) as caught:
+            warnings.simplefilter("always")
+            get_chat_model("x-ai/grok-4.3", provider="openrouter", **extra)
+
+        assert not [w for w in caught if "openrouter" in str(w.message).lower()]
+        call_kwargs = mock_init.call_args[1]
+        assert call_kwargs["app_url"] == "https://github.com/EvoScientist/EvoScientist"
+        assert call_kwargs["app_title"] == "EvoScientist"
+
     @patch("EvoScientist.llm.models.init_chat_model")
     def test_non_openrouter_providers_get_no_app_attribution(
         self, mock_init, monkeypatch