diff --git a/explain/claude_agent.py b/explain/claude_agent.py
index c58aee1..7b3970f 100644
--- a/explain/claude_agent.py
+++ b/explain/claude_agent.py
@@ -121,6 +121,7 @@ async def ask(self, question: str, port: int, tools: list[str]) -> str:
                 "opus",
                 "--mcp-config",
                 mcp_config_path,
+                "--strict-mcp-config",
                 "--allowedTools",
                 allowed_tools,
                 "--output-format",