diff --git a/package/x11r7/xapp_rstart/Config.in b/package/x11r7/xapp_rstart/Config.in
index 1bf61b3a34..3c1d5a9e1e 100644
--- a/package/x11r7/xapp_rstart/Config.in
+++ b/package/x11r7/xapp_rstart/Config.in
@@ -1,5 +1,6 @@
 config BR2_PACKAGE_XAPP_RSTART
 	bool "rstart"
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_XLIB_LIBX11
 	help
 	  X.Org rstart application