--- configure.ac.orig	2013-05-28 09:05:57.000000000 +0400
+++ configure.ac	2013-05-28 09:06:36.000000000 +0400
@@ -12,8 +12,8 @@
 
 AC_PROG_CC
 
-if test "x$GCC" = xyes ; then
-  CFLAGS="-O3 $CFLAGS"
+if test "x$CC" = xyes ; then
+  CFLAGS="$CFLAGS"
 fi
 
 m4_include([libeio.m4])