duplicate symbol: rtuns

[ndeffayet]

MLVPN-2.3.5
OS: FreeBSD 14.0
Configure settings: ./configure --prefix=/usr

During build with make, I get the following error:

CCLD     mlvpn
ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-filters.o:(.bss+0x0)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-control.o:(.bss+0x0)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-tuntap_bsd.o:(.bss+0x0)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-mlvpn.o:(.bss+0x1828)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-tuntap_generic.o:(.bss+0x0)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-wrr.o:(.bss+0x808)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-privsep.o:(.bss+0x410)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-config.o:(.bss+0x0)

ld: error: duplicate symbol: rtuns
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-buffer.o:(rtuns)
>>> defined at mlvpn.h:133 (./mlvpn.h:133)
>>>            mlvpn-configlib.o:(.bss+0x0)
cc: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 1

Workaround:
# make CFLAGS="-Wl,--allow-multiple-definition"