diff --git a/sys/sys/elf_common.h b/sys/sys/elf_common.h
index a13a694d29c..7edfcfc9ca2 100644
--- a/sys/sys/elf_common.h
+++ b/sys/sys/elf_common.h
@@ -796,6 +796,7 @@ typedef struct {
 #define	NT_FREEBSD_FCTL_PROTMAX_DISABLE	0x00000002
 #define	NT_FREEBSD_FCTL_STKGAP_DISABLE	0x00000004
 #define	NT_FREEBSD_FCTL_WXNEEDED	0x00000008
+#define	NT_FREEBSD_FCTL_LA48		0x00000010
 
 /* Values for n_type.  Used in core files. */
 #define	NT_PRSTATUS	1	/* Process status. */
diff --git a/usr.bin/elfctl/elfctl.c b/usr.bin/elfctl/elfctl.c
index f371d9cd6f5..591258fad72 100644
--- a/usr.bin/elfctl/elfctl.c
+++ b/usr.bin/elfctl/elfctl.c
@@ -67,6 +67,7 @@ static struct ControlFeatures featurelist[] = {
 	    "Disable implicit PROT_MAX" },
 	{ "stackgap",	NT_FREEBSD_FCTL_STKGAP_DISABLE, "Disable stack gap" },
 	{ "wxneeded",	NT_FREEBSD_FCTL_WXNEEDED, "Requires W+X mappings" },
+	{ "la48",	NT_FREEBSD_FCTL_LA48, "amd64: Limit user VA to 48bit" },
 };
 
 static struct option long_opts[] = {