diff --git a/sched/irq/irq.h b/sched/irq/irq.h
index 7a394ec6cb9..f36075657c3 100644
--- a/sched/irq/irq.h
+++ b/sched/irq/irq.h
@@ -123,7 +123,6 @@ extern volatile spinlock_t g_cpu_irqlock;
 
 /* Used to keep track of which CPU(s) hold the IRQ lock. */
 
-extern volatile spinlock_t g_cpu_irqsetlock;
 extern volatile cpu_set_t g_cpu_irqset;
 
 /* Handles nested calls to enter_critical section from interrupt handlers */