Valgrind check: No rule to make target 'check-TESTS'

Hello,

I would like to use ax_valgrind_check.m4, but I have the following
error:

$ make check-valgrind-memcheck 
make check-TESTS \
        TESTS_ENVIRONMENT=" env VALGRIND=valgrind G_SLICE=always-malloc,debug-blocks G_DEBUG=fatal-warnings,fatal-criticals,gc-friendly" \
        LOG_COMPILER="/bin/sh ./libtool   --mode=execute valgrind  --error-exitcode=1 --num-callers=30" \
        LOG_FLAGS="--tool=memcheck --leak-check=full --show-reachable=no" \
        TEST_SUITE_LOG=test-suite-memcheck.log
make[1]: Entering directory '/home/seb/gnome/gspell'
make[1]: *** No rule to make target 'check-TESTS'.  Stop.
make[1]: Leaving directory '/home/seb/gnome/gspell'
Makefile:1220: recipe for target 'check-valgrind-memcheck' failed
make: *** [check-valgrind-memcheck] Error 2


There is no check-TESTS target in the project that I maintain, here
gspell. See its testsuite/Makefile.am:
https://git.gnome.org/browse/gspell/tree/testsuite/Makefile.am?h=1.1.2

It's basically using:
noinst_PROGRAMS = $(UNIT_TEST_PROGS)
TESTS = $(UNIT_TEST_PROGS)
UNIT_TEST_PROGS = ...

So, is this a bug in ax_valgrind_check.m4? Or does it make some
assumptions that are not applied in gspell?

Thanks in advance,
Sébastien