diff --git a/samd/samd51/clocks.c b/samd/samd51/clocks.c
index 384f845..c780d2d 100644
--- a/samd/samd51/clocks.c
+++ b/samd/samd51/clocks.c
@@ -121,6 +121,7 @@ void clock_init(void) {
     enable_clock_generator_sync(1, GCLK_GENCTRL_SRC_DFLL_Val, 1, false);
     enable_clock_generator_sync(4, GCLK_GENCTRL_SRC_DPLL0_Val, 1, false);
     enable_clock_generator_sync(5, GCLK_GENCTRL_SRC_DFLL_Val, 24, false);
+    enable_clock_generator_sync(6, GCLK_GENCTRL_SRC_DFLL_Val, 4, false);
 
     init_clock_source_dpll0();