diff --git a/libc/kernel/uapi/linux/kvm.h b/libc/kernel/uapi/linux/kvm.h
index affb6a5..768f57e 100644
--- a/libc/kernel/uapi/linux/kvm.h
+++ b/libc/kernel/uapi/linux/kvm.h
@@ -928,6 +928,7 @@
 #define KVM_CAP_VM_DISABLE_NX_HUGE_PAGES 220
 #define KVM_CAP_S390_ZPCI_OP 221
 #define KVM_CAP_S390_CPU_TOPOLOGY 222
+#define KVM_CAP_DIRTY_LOG_RING_ACQ_REL 223
 #ifdef KVM_CAP_IRQ_ROUTING
 struct kvm_irq_routing_irqchip {
   __u32 irqchip;