diff --git a/ports/stm32/boards/stm32n657_af.csv b/ports/stm32/boards/stm32n657_af.csv
index 35e305a376..9bdb196f88 100644
--- a/ports/stm32/boards/stm32n657_af.csv
+++ b/ports/stm32/boards/stm32n657_af.csv
@@ -37,6 +37,6 @@ PortG,PG2 ,             ,                   ,                              ,
 PortG,PG5 ,             ,                   ,                              ,                                    ,                                                   ,                                                      ,                                                        ,USART2_CTS                                                   ,                                  ,                                                                     ,                                             ,                                                       ,                                                            ,                                                ,                       ,        ,
 PortG,PG8 ,             ,                   ,                              ,                                    ,                                                   ,                                                      ,                                                        ,                                                             ,                                  ,                                                                     ,                                             ,SDMMC2_D1                                              ,                                                            ,                                                ,                       ,        ,
 PortG,PG12,             ,TIM17_CH1          ,                              ,                                    ,                                                   ,                                                      ,                                                        ,                                                             ,                                  ,                                                                     ,                                             ,                                                       ,                                                            ,                                                ,                       ,        ,
-PortG,PG13,             ,                   ,TIM4_CH1                      ,                                    ,                                                   ,                                                      ,                                                        ,                                                             ,                                  ,                                                                     ,                                             ,                                                       ,                                                            ,                                                ,                       ,        ,
+PortG,PG13,             ,                   ,TIM4_CH1                      ,                                    ,                                                   ,                                                      ,                                                        ,USART3_RTS                                                   ,                                  ,                                                                     ,                                             ,                                                       ,                                                            ,                                                ,                       ,        ,
 PortG,PG15,             ,                   ,                              ,                                    ,                                                   ,                                                      ,                                                        ,                                                             ,                                  ,                                                                     ,                                             ,                                                       ,                                                            ,                                                ,                       ,        ,ADC12_INP7/ADC12_INN3
 PortC,PH2 ,             ,                   ,                              ,                                    ,                                                   ,                                                      ,                                                        ,                                                             ,                                  ,                                                                     ,SDMMC1_CMD                                   ,                                                       ,                                                            ,                                                ,                       ,        ,