diff --git a/sys/x86/include/xen/xen-os.h b/sys/x86/include/xen/xen-os.h
--- a/sys/x86/include/xen/xen-os.h
+++ b/sys/x86/include/xen/xen-os.h
@@ -43,6 +43,9 @@
 /* If non-zero, the hypervisor has been configured to use a direct vector */
 extern int xen_vector_callback_enabled;
 
+/* Signal whether the event channel vector requires EOI at the lapic */
+extern bool xen_evtchn_needs_ack;
+
 /* tunable for disabling PV disks */
 extern int xen_disable_pv_disks;
 
diff --git a/sys/xen/hvm.h b/sys/xen/hvm.h
--- a/sys/xen/hvm.h
+++ b/sys/xen/hvm.h
@@ -102,6 +102,5 @@
 void xen_hvm_resume(bool suspend_cancelled);
 
 extern uint32_t hvm_start_flags;
-extern bool xen_evtchn_needs_ack;
 
 #endif	/* __XEN_HVM_H__ */