diff --git a/sys/arm/at91/at91_machdep.c b/sys/arm/at91/at91_machdep.c
index 0f6b79ba767b..293a352cb101 100644
--- a/sys/arm/at91/at91_machdep.c
+++ b/sys/arm/at91/at91_machdep.c
@@ -117,8 +117,6 @@ extern struct bus_space at91_bs_tag;
 
 struct pv_addr kernel_pt_table[NUM_KERNEL_PTS];
 
-extern uint32_t at91_master_clock;
-
 /* Static device mappings. */
 const struct arm_devmap_entry at91_devmap[] = {
 	/*