diff --git a/ollama/_client.py b/ollama/_client.py
index 8dfce82..51239d9 100644
--- a/ollama/_client.py
+++ b/ollama/_client.py
@@ -801,7 +801,12 @@ async def web_search(self, query: str, max_results: int = 3) -> WebSearchRespons
 
     Returns:
       WebSearchResponse with the search results
+    Raises:
+      ValueError: If OLLAMA_API_KEY environment variable is not set
     """
+    if not self._client.headers.get('authorization', '').startswith('Bearer '):
+      raise ValueError('Authorization header with Bearer token is required for web search')
+
     return await self._request(
       WebSearchResponse,
       'POST',
@@ -821,7 +826,12 @@ async def web_fetch(self, url: str) -> WebFetchResponse:
 
     Returns:
       WebFetchResponse with the fetched result
+    Raises:
+      ValueError: If OLLAMA_API_KEY environment variable is not set
     """
+    if not self._client.headers.get('authorization', '').startswith('Bearer '):
+      raise ValueError('Authorization header with Bearer token is required for web fetch')
+
     return await self._request(
       WebFetchResponse,
       'POST',
diff --git a/tests/test_client.py b/tests/test_client.py
index 7b7ab38..981b1aa 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -1397,6 +1397,24 @@ def test_client_web_fetch_requires_bearer_auth_header(monkeypatch: pytest.Monkey
     client.web_fetch('https://example.com')
 
 
+async def test_async_client_web_search_requires_bearer_auth_header(monkeypatch: pytest.MonkeyPatch):
+  monkeypatch.delenv('OLLAMA_API_KEY', raising=False)
+
+  client = AsyncClient()
+
+  with pytest.raises(ValueError, match='Authorization header with Bearer token is required for web search'):
+    await client.web_search('test query')
+
+
+async def test_async_client_web_fetch_requires_bearer_auth_header(monkeypatch: pytest.MonkeyPatch):
+  monkeypatch.delenv('OLLAMA_API_KEY', raising=False)
+
+  client = AsyncClient()
+
+  with pytest.raises(ValueError, match='Authorization header with Bearer token is required for web fetch'):
+    await client.web_fetch('https://example.com')
+
+
 def _mock_request_web_search(self, cls, method, url, json=None, **kwargs):
   assert method == 'POST'
   assert url == 'https://ollama.com/api/web_search'