[blitz.mod] Release command not working

[GWRon]

I took this code from the docs (and made it "strict") :

https://blitzmax.org/docs/en/api/brl/brl.blitz/#release

Rem
Release removes the internal reference caused by creating an integer handle to a type.
End Rem

Type MyType
    Field bigmap[1024*1024]
End Type

GCCollect
Print GCMemAlloced()

Local a:Mytype=New MyType
GCCollect
Print GCMemAlloced()

Release a
GCCollect
Print GCMemAlloced()

Trying to execute it leads to:

Building untitled1
[ 23%] Processing:untitled1.bmx
Compile Error: Subexpression for release must be an integer variable
[/home/ronny/Arbeit/Tools/BlitzMaxNG/tmp/untitled1.bmx;16;0]

So I guess Release() might not be implemented as expected.