autoconf 2.64 warning: AC_REQUIRE: `AC_PROG_CC' was expanded before it was required

[Carsten Heinrici]

we are sually working with autoconf 2.63, but I just have to work on a
system with 2.64 installed and run into the warning:

configure.in:40: warning: AC_REQUIRE: `AC_PROG_CC' was expanded before
it was required
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/autoconf/c.m4:433:
AC_LANG_COMPILER(C) is expanded from...
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/autoconf/lang.m4:315:
AC_LANG_COMPILER_REQUIRE is expanded from...
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/autoconf/general.m4:2665:
AC_LINK_IFELSE is expanded from...
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/autoconf/general.m4:2674:
AC_TRY_LINK is expanded from...
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/m4sugar/m4sh.m4:620:
AS_IF is expanded from...
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/autoconf/general.m4:2018:
AC_CACHE_VAL is expanded from...
/usr/src/packages/autoconf/26/autoconf2.5-2.64-1/src/autoconf-2.64/lib/autoconf/general.m4:2039:
AC_CACHE_CHECK is expanded from...
../ingeconf/icgeneral.m4:2064: IC_CHECK_THREADSAFE is expanded from...
../ingeconf/icgeneral.m4:144: IC_CONFIG_C_ is expanded from...
../ingeconf/icgeneral.m4:116: IC_CONFIG_C is expanded from...
configure.in:40: the top level

Can anybody give any advice about what is wrong?

Thanks,
Carsten Heinrici