diff --git a/configs/saml21-xplained/include/board.h b/configs/saml21-xplained/include/board.h
index 839d9fb8c2c..81bf329ae51 100644
--- a/configs/saml21-xplained/include/board.h
+++ b/configs/saml21-xplained/include/board.h
@@ -232,6 +232,7 @@
  *   BOARD_FDPLL96M_REFCLK          - See  OSCCTRL_DPLLCTRLB_REFLCK_* definitions
  *   BOARD_FDPLL96M_REFCLK_CLKGEN   - See GCLK_CLKCTRL_GEN* definitions
  *   BOARD_FDPLL96M_LOCKTIME_ENABLE - Boolean (defined / not defined)
+ *   BOARD_FDPLL96M_LOCKTIME_CLKGEN - See GCLK_CLKCTRL_GEN* definitions
  */
 
 #undef  BOARD_FDPLL96M_ENABLE