diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index f23a359c8f46..2735da5f839e 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -58,9 +58,11 @@ void irq_work_sync(struct irq_work *work);
 
 void irq_work_run(void);
 bool irq_work_needs_cpu(void);
+void irq_work_single(void *arg);
 #else
 static inline bool irq_work_needs_cpu(void) { return false; }
 static inline void irq_work_run(void) { }
+static inline void irq_work_single(void *arg) { }
 #endif
 
 #endif /* _LINUX_IRQ_WORK_H */
diff --git a/kernel/smp.c b/kernel/smp.c
index 4dec04f7fdc5..c80486a7e3b8 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -194,8 +194,6 @@ void generic_smp_call_function_single_interrupt(void)
 	flush_smp_call_function_queue(true);
 }
 
-extern void irq_work_single(void *);
-
 /**
  * flush_smp_call_function_queue - Flush pending smp-call-function callbacks
  *