diff --git a/configure.ac b/configure.ac
index 7f5b73bc..163b7860 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,6 +28,7 @@ AC_INIT([xlibre-xf86-video-ati],
         [xlibre-xf86-video-ati])
 
 AC_CONFIG_SRCDIR([Makefile.am])
+AC_USE_SYSTEM_EXTENSIONS
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIR([m4])