--- a/build/autoconf/hotfixes.m4
+++ b/build/autoconf/hotfixes.m4
@@ -11,14 +11,13 @@ dnl prints is replaced with:
 dnl   #define posix_memalign innocuous_posix_memalign
 dnl   #include "theinclude"
 dnl   #undef posix_memalign
 dnl This avoids double declaration of that function when the header normally
 dnl declares it, while the test itself is just expecting the function not to be
 dnl declared at all, and declares it differently (which doesn't matter for the
 dnl test itself).
 dnl More recent versions of autoconf are essentially doing this.
-define([ac_cv_func_], [ac_cv_func2_])dnl
 define([_AC_CHECK_FUNC],defn([AC_CHECK_FUNC]))dnl
 define([AC_CHECK_FUNC], [dnl
 patsubst(_AC_CHECK_FUNC($@), [#include.*$], [#define $1 innocuous_$1
 \&
 #undef $1])])dnl