diff --git a/package/x11r7/xdriver_xf86-video-tdfx/xdriver_xf86-video-tdfx.mk b/package/x11r7/xdriver_xf86-video-tdfx/xdriver_xf86-video-tdfx.mk
index 8975334f90..14c40e4d89 100644
--- a/package/x11r7/xdriver_xf86-video-tdfx/xdriver_xf86-video-tdfx.mk
+++ b/package/x11r7/xdriver_xf86-video-tdfx/xdriver_xf86-video-tdfx.mk
@@ -16,7 +16,7 @@ XDRIVER_XF86_VIDEO_TDFX_DEPENDENCIES = \
 	xserver_xorg-server
 
 ifeq ($(BR2_PACKAGE_MESA3D_DRI_DRIVER),)
-XDRIVER_XF86_VIDEO_TDFX_CONF_OPTS = --disable-dri
+XDRIVER_XF86_VIDEO_TDFX_CONF_OPTS += --disable-dri
 endif
 
 $(eval $(autotools-package))