diff --git a/etc/rc.initdiskless b/etc/rc.initdiskless
index 1ba8c81e6877..3e9c2c700990 100644
--- a/etc/rc.initdiskless
+++ b/etc/rc.initdiskless
@@ -197,8 +197,9 @@ handle_remount() { # $1 = mount point
 
 # Create a generic memory disk.
 # The 'auto' parameter will attempt to use tmpfs(5), falls back to md(4).
+# $1 is size in 512-byte sectors, $2 is the mount point.
 mount_md() {
-    /sbin/mdmfs $flags -s $1 auto $2
+    /sbin/mdmfs -s $1 auto $2
 }
 
 # Create the memory filesystem if it has not already been created