diff --git a/package/x11r7/xlib_libSM/xlib_libSM.mk b/package/x11r7/xlib_libSM/xlib_libSM.mk
index a8d1eff1b5..bdbda3fe56 100644
--- a/package/x11r7/xlib_libSM/xlib_libSM.mk
+++ b/package/x11r7/xlib_libSM/xlib_libSM.mk
@@ -11,4 +11,9 @@ XLIB_LIBSM_INSTALL_STAGING = YES
 XLIB_LIBSM_DEPENDENCIES = xlib_libICE xlib_xtrans xproto_xproto
 XLIB_LIBSM_CONF_OPT = --without-libuuid
 
+ifneq ($(BR2_HAVE_DOCUMENTATION),y)
+# documentation generation is slow
+XLIB_LIBSM_CONF_OPT += --disable-docs
+endif
+
 $(eval $(autotools-package))