diff --git a/configure.ac b/configure.ac
index 1c203984..d747fe23 100644
--- a/configure.ac
+++ b/configure.ac
@@ -31,7 +31,7 @@ AC_PROG_CC
 
 AC_HEADER_STDC
 AC_SYS_LARGEFILE
-AC_USE_SYSTEM_MACROS
+AC_USE_SYSTEM_EXTENSIONS
 
 PKG_CHECK_MODULES(PTHREADSTUBS, pthread-stubs)
 AC_SUBST(PTHREADSTUBS_CFLAGS)