Index: src/github.com/travisjeffery/jocko/vendor/github.com/tysontate/gommap/mmap_freebsd_386.go
--- src/github.com/travisjeffery/jocko/vendor/github.com/tysontate/gommap/mmap_freebsd_386.go.orig	2017-10-13 21:03:52.965014000 +0200
+++ src/github.com/travisjeffery/jocko/vendor/github.com/tysontate/gommap/mmap_freebsd_386.go	2017-10-13 20:57:37.000000000 +0200
@@ -0,0 +1,12 @@
+package gommap
+
+import "syscall"
+
+func mmap_syscall(addr, length, prot, flags, fd uintptr, offset int64) (uintptr, error) {
+	page := uintptr(offset / 4096)
+	if offset != int64(page)*4096 {
+		return 0, syscall.EINVAL
+	}
+	addr, _, err := syscall.Syscall6(syscall.SYS_MMAP2, addr, length, prot, flags, fd, page)
+	return addr, err
+}
Index: src/github.com/travisjeffery/jocko/vendor/github.com/tysontate/gommap/mmap_freebsd_amd64.go
--- src/github.com/travisjeffery/jocko/vendor/github.com/tysontate/gommap/mmap_freebsd_amd64.go.orig	2017-10-13 21:03:55.833917000 +0200
+++ src/github.com/travisjeffery/jocko/vendor/github.com/tysontate/gommap/mmap_freebsd_amd64.go	2017-10-13 20:57:37.000000000 +0200
@@ -0,0 +1,8 @@
+package gommap
+
+import "syscall"
+
+func mmap_syscall(addr, length, prot, flags, fd uintptr, offset int64) (uintptr, error) {
+	addr, _, err := syscall.Syscall6(syscall.SYS_MMAP, addr, length, prot, flags, fd, uintptr(offset))
+	return addr, err
+}