diff --git a/tests/test_beta_flags.py b/tests/test_beta_flags.py
index 4fe2f06..7e312b5 100644
--- a/tests/test_beta_flags.py
+++ b/tests/test_beta_flags.py
@@ -50,11 +50,12 @@ async def test_beta_flags_collected_from_tools():
             tools=tools_with_flags
         )
 
-        # Check that beta flag was added to headers
+        # Check that beta flag was added to headers (merged with hardcoded flags)
         call_args = mock_client.post.call_args
         headers = call_args[1]["headers"]
         assert "anthropic-beta" in headers
-        assert headers["anthropic-beta"] == "computer-use-2025-11-24"
+        # Should include hardcoded flags + tool flag, sorted alphabetically
+        assert headers["anthropic-beta"] == "claude-code-20250219,computer-use-2025-11-24,context-management-2025-06-27,oauth-2025-04-20"
 
 
 @pytest.mark.asyncio
@@ -99,5 +100,5 @@ async def test_multiple_beta_flags_joined():
         call_args = mock_client.post.call_args
         headers = call_args[1]["headers"]
         assert "anthropic-beta" in headers
-        # Should be sorted alphabetically and joined with comma
-        assert headers["anthropic-beta"] == "flag-a,flag-b"
+        # Should include hardcoded flags + tool flags, sorted alphabetically and joined with comma
+        assert headers["anthropic-beta"] == "claude-code-20250219,context-management-2025-06-27,flag-a,flag-b,oauth-2025-04-20"
diff --git a/tests/test_oauth_utils.py b/tests/test_oauth_utils.py
index c84af4c..75ec75b 100644
--- a/tests/test_oauth_utils.py
+++ b/tests/test_oauth_utils.py
@@ -17,7 +17,7 @@ def test_get_auth_headers_oauth():
     assert "Authorization" in headers
     assert headers["Authorization"] == "Bearer sk-ant-oat01-xxx"
     assert "x-api-key" not in headers
-    assert headers["anthropic-beta"] == "claude-code-20250219,oauth-2025-04-20"
+    assert headers["anthropic-beta"] == "claude-code-20250219,oauth-2025-04-20,context-management-2025-06-27"
 
 
 def test_get_auth_headers_api_key():