diff --git a/mem/mem_freebsd.go b/mem/mem_freebsd.go
index 1fa880b8..2d65f803 100644
--- a/mem/mem_freebsd.go
+++ b/mem/mem_freebsd.go
@@ -39,7 +39,7 @@ func VirtualMemoryWithContext(ctx context.Context) (*VirtualMemoryStat, error) {
 	if err != nil {
 		return nil, err
 	}
-	buffers, err := unix.SysctlUint32("vfs.bufspace")
+	buffers, err := unix.SysctlUint64("vfs.bufspace")
 	if err != nil {
 		return nil, err
 	}