diff --git a/xen/include/xen/vpci.h b/xen/include/xen/vpci.h
index 9ea66e033f..3f32de9d7e 100644
--- a/xen/include/xen/vpci.h
+++ b/xen/include/xen/vpci.h
@@ -247,7 +247,7 @@ static inline void vpci_write(pci_sbdf_t sbdf, unsigned int reg,
     ASSERT_UNREACHABLE();
 }
 
-static inline bool vpci_process_pending(struct vcpu *v)
+static inline bool __must_check vpci_process_pending(struct vcpu *v)
 {
     ASSERT_UNREACHABLE();
     return false;