diff --git a/configure.ac b/configure.ac
index 7d43cad..ed86210 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,7 +44,7 @@ AC_TYPE_SIZE_T
 # Checks for library functions.
 AC_FUNC_VPRINTF
 AC_FUNC_MEMCMP
-AC_FUNC_REALLOC
+AC_CHECK_FUNCS([realloc])
 AC_CHECK_FUNCS(strcasecmp strdup strerror snprintf vsnprintf vasprintf open vsyslog strncasecmp setlocale)
 AC_CHECK_DECLS([INFINITY], [], [], [[#include <math.h>]])
 AC_CHECK_DECLS([nan], [], [], [[#include <math.h>]])