Exim 4.93.0.4 compile error

Hi when updating EXIM to 4.93.0.4 I get an error

error: 'for' loop initial declarations are only allowed in C99 mode

It's in the log down below.

Executing /usr/local/directadmin/plugins/custombuild/admin/build exim...
Found /usr/local/directadmin/custombuild/exim-4.93.0.4.tar.gz
Extracting ...
Done.
--2020-01-11 20:21:11-- https://files6.directadmin.com/services/custombuild/Makefile
Resolving files6.directadmin.com (files6.directadmin.com)... 2001:16e8:1:c:62:148:174:106, 62.148.174.106
Connecting to files6.directadmin.com (files6.directadmin.com)|2001:16e8:1:c:62:148:174:106|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 48603 (47K) [text/plain]
Saving to: 'Local/Makefile'

0K .......... .......... .......... .......... ....... 100% 12.9M=0.004s

2020-01-11 20:21:11 (12.9 MB/s) - 'Local/Makefile' saved [48603/48603]

Trying to make exim...
/bin/sh scripts/source_checks

>>> Creating links to source files...
>>> Creating lookups/Makefile for building dynamic modules
>>> New Makefile & lookups/Makefile installed
>>> Use "make makefile" if you need to force rebuilding of the makefile

make[1]: Entering directory `/usr/local/directadmin/custombuild/exim-4.93.0.4/build-Linux-x86_64'
/bin/sh ../scripts/Configure-os.c
cc buildconfig.c
/bin/sh ../scripts/Configure-os.h
cc exim_lock.c
cc -o exim_lock
>>> exim_lock utility built

/bin/sh ../scripts/Configure-config.h "make"
make[2]: Entering directory `/usr/local/directadmin/custombuild/exim-4.93.0.4/build-Linux-x86_64'
make[2]: `buildconfig' is up to date.
make[2]: Leaving directory `/usr/local/directadmin/custombuild/exim-4.93.0.4/build-Linux-x86_64'
Building configuration file config.h
>>> config.h built

cc -DMACRO_PREDEF macro_predef.c
cc -DMACRO_PREDEF globals.c
macro_predef.c: In function 'options_from_list':
macro_predef.c:83:1: error: 'for' loop initial declarations are only allowed in C99 mode
for (int i = 0; i < nopt; i++) if (*(s = US opts.name) && *s != '*')
^
macro_predef.c:83:1: note: use option -std=c99 or -std=gnu99 to compile your code
make[1]: *** [macro_predef.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make[1]: Leaving directory `/usr/local/directadmin/custombuild/exim-4.93.0.4/build-Linux-x86_64'
make: *** [all] Error 2

Done!

Help?