diff --git a/libc/kernel/uapi/linux/ndctl.h b/libc/kernel/uapi/linux/ndctl.h
index 742fbad..e47091f 100644
--- a/libc/kernel/uapi/linux/ndctl.h
+++ b/libc/kernel/uapi/linux/ndctl.h
@@ -157,5 +157,6 @@
 #define NVDIMM_FAMILY_HPE1 1
 #define NVDIMM_FAMILY_HPE2 2
 #define NVDIMM_FAMILY_MSFT 3
+#define NVDIMM_FAMILY_HYPERV 4
 #define ND_IOCTL_CALL _IOWR(ND_IOCTL, ND_CMD_CALL, struct nd_cmd_pkg)
 #endif