diff --git a/qemu/target/arm/cpu.h b/qemu/target/arm/cpu.h
index ca1f2692..34dabc7c 100644
--- a/qemu/target/arm/cpu.h
+++ b/qemu/target/arm/cpu.h
@@ -1356,7 +1356,7 @@ uint32_t arm_phys_excp_target_el(CPUState *cs, uint32_t excp_idx,
 
 /* Interface between CPU and Interrupt controller.  */
 void armv7m_nvic_set_pending(void *opaque, int irq);
-int armv7m_nvic_acknowledge_irq(void *opaque);
+void armv7m_nvic_acknowledge_irq(void *opaque);
 void armv7m_nvic_complete_irq(void *opaque, int irq);
 
 /* Interface for defining coprocessor registers.