diff --git a/configure.ac b/configure.ac
index 5589844..deb48eb 100755
--- a/configure.ac
+++ b/configure.ac
@@ -77,6 +77,7 @@
 AC_PROG_RANLIB
 AC_PROG_EGREP
 PKG_PROG_PKG_CONFIG
+AC_PROG_CC_C99
 
 dnl autoconf 2.59 appears not to support AC_PROG_SED
 dnl AC_PROG_SED
@@ -145,7 +146,6 @@
         AC_MSG_RESULT([autodetecting])
 
         AC_C_FLAG([-diag-error 10006])
-        AC_C_FLAG([-std=gnu99])
         AC_C_FLAG([-g])
         AC_C_FLAG([-Os], [
           AC_C_FLAG([-O2])