diff --git a/mcp/streamable.go b/mcp/streamable.go
index 76f2b0e4..4236c88e 100644
--- a/mcp/streamable.go
+++ b/mcp/streamable.go
@@ -1782,14 +1782,14 @@ func (c *streamableClientConn) Write(ctx context.Context, msg jsonrpc.Message) e
 			// Failure to set headers means that the request was not sent.
 			// Wrap with ErrRejected so the jsonrpc2 connection doesn't set writeErr
 			// and permanently break the connection.
-			return nil, nil, fmt.Errorf("%s: %w: %v", requestSummary, jsonrpc2.ErrRejected, err)
+			return nil, nil, fmt.Errorf("%s: %w: %w", requestSummary, jsonrpc2.ErrRejected, err)
 		}
 		resp, err := c.client.Do(req)
 		if err != nil {
 			// Any error from client.Do means the request didn't reach the server.
 			// Wrap with ErrRejected so the jsonrpc2 connection doesn't set writeErr
 			// and permanently break the connection.
-			err = fmt.Errorf("%s: %w: %v", requestSummary, jsonrpc2.ErrRejected, err)
+			err = fmt.Errorf("%s: %w: %w", requestSummary, jsonrpc2.ErrRejected, err)
 		}
 		return req, resp, err
 	}