--- libeio/configure.ac	2008/10/22 18:15:36	1.4
+++ libeio/configure.ac	2011/01/07 22:00:12	1.5
@@ -14,7 +14,7 @@
 fi
 
 dnl somebody will forgive me
-CFLAGS="-D_GNU_SOURCE"
+CFLAGS="-D_GNU_SOURCE $CFLAGS"
 
 m4_include([libeio.m4])