diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index eb4bfcb6f9..bec06df60b 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -63,6 +63,7 @@
 #define __HYPERVISOR_hvm_op               34
 #define __HYPERVISOR_sysctl               35
 #define __HYPERVISOR_domctl               36
+#define __HYPERVISOR_kexec_op             37
 
 /* Architecture-specific hypercall definitions. */
 #define __HYPERVISOR_arch_0               48