diff --git a/configure.ac b/configure.ac
index ca9b9473..020f21e5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,7 +44,7 @@ fi
 # Set up the compiler in two different ways and say yes we may want to install.
 AC_PROG_CC
 AM_PROG_CC_C_O
-AC_PROG_CC_C99
+m4_version_prereq(2.70, [AC_PROG_CC], [AC_PROG_CC_C99])
 AC_PROG_CPP
 AC_PROG_EGREP
 AC_PROG_INSTALL