diff --git a/marimo/_server/ai/mcp/transport.py b/marimo/_server/ai/mcp/transport.py
index 724247ffd5d..a27a638ba7f 100644
--- a/marimo/_server/ai/mcp/transport.py
+++ b/marimo/_server/ai/mcp/transport.py
@@ -106,9 +106,12 @@ class MCPTransportRegistry:
     """Registry for MCP transport connectors."""
 
     def __init__(self) -> None:
+        # Moved local names outside of dict literal to avoid repeated attribute lookups
+        stdio = MCPTransportType.STDIO
+        http = MCPTransportType.STREAMABLE_HTTP
         self._connectors: dict[MCPTransportType, MCPTransportConnector] = {
-            MCPTransportType.STDIO: StdioTransportConnector(),
-            MCPTransportType.STREAMABLE_HTTP: StreamableHTTPTransportConnector(),
+            stdio: StdioTransportConnector(),
+            http: StreamableHTTPTransportConnector(),
         }
 
     def get_connector(
@@ -125,6 +128,7 @@ def get_connector(
         Raises:
             ValueError: If transport type is not supported
         """
-        if transport_type not in self._connectors:
+        try:
+            return self._connectors[transport_type]
+        except KeyError:
             raise ValueError(f"Unsupported transport type: {transport_type}")
-        return self._connectors[transport_type]