diff --git a/arch/arm/src/samdl/saml_clockconfig.c b/arch/arm/src/samdl/saml_clockconfig.c
index a3d82aa4768..e2c77d6169d 100644
--- a/arch/arm/src/samdl/saml_clockconfig.c
+++ b/arch/arm/src/samdl/saml_clockconfig.c
@@ -73,6 +73,23 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+/* Force enabling of the FDPLL reference clock */
+
+#ifdef BOARD_FDPLL96M_ENABLE
+#  if BOARD_FDPLL96M_REFCLK == OSCCTRL_DPLLCTRLB_REFLCK_XOSC && \
+      !defined(BOARD_XOSC_ENABLE)
+#    warning Forcing BOARD_XOSC_ENABLE for FDPLL96M
+#    define BOARD_XOSC_ENABLE 1
+#  elif BOARD_FDPLL96M_REFCLK == OSCCTRL_DPLLCTRLB_REFLCK_XOSCK32K && \
+        !defined(BOARD_XOSC32K_ENABLE)
+#    warning Forcing BOARD_XOSC32K_ENABLE for FDPLL96M
+#    define BOARD_XOSC32K_ENABLE 1
+#  elif BOARD_FDPLL96M_REFCLK == OSCCTRL_DPLLCTRLB_REFLCK_GLCK && \
+        !defined(BOARD_GCLK_ENABLE)
+#    warning Forcing BOARD_GCLK_ENABLE for FDPLL96M
+#    define BOARD_GCLK_ENABLE 1
+#  endif
+#endif
 
 /****************************************************************************
  * Private Types
diff --git a/configs/saml21-xplained/include/board.h b/configs/saml21-xplained/include/board.h
index 3636e62c5db..309633b1d2f 100644
--- a/configs/saml21-xplained/include/board.h
+++ b/configs/saml21-xplained/include/board.h
@@ -226,6 +226,14 @@
 
 #define BOARD_DFLL48M_FREQUENCY          (48000000)
 
+/* Fractional Digital Phase Locked Loop configuration.
+ *
+ *   BOARD_FDPLL96M_REFCLK - See  OSCCTRL_DPLLCTRLB_REFLCK_* definitions
+ */
+
+#undef  BOARD_FDPLL96M_ENABLE
+#define BOARD_FDPLL96M_REFCLK            OSCCTRL_DPLLCTRLB_REFLCK_XOSC
+
 /* GCLK Configuration
  *
  * Global enable/disable.