The hyperfine coupling constants Aα on p. 831 of NaFe4Sb12 (Fig. 1) are too large by a factor of 10. This error comes from conversion of kOe and T. The correct hyperfine coupling constants are determined to be Aα1=−1.449 kOe/μB above TC and Aα2=−1.155 kOe/μB below TC. We apologize for this error and any confusion that they may have caused. The results and conclusions of our paper remain unaffected.