diff --git a/package/blackbox/Config.in b/package/blackbox/Config.in
index 70f7eb4b57..c183133e99 100644
--- a/package/blackbox/Config.in
+++ b/package/blackbox/Config.in
@@ -2,6 +2,7 @@ config BR2_PACKAGE_BLACKBOX
 	bool "blackbox"
 	depends on BR2_PACKAGE_XORG7
 	depends on BR2_INSTALL_LIBSTDCPP
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_LIBICONV if !BR2_ENABLE_LOCALE
 	select BR2_PACKAGE_XLIB_LIBX11
 	help