diff --git a/package/ncdu/Config.in b/package/ncdu/Config.in
index dac744410b..0e4403444f 100644
--- a/package/ncdu/Config.in
+++ b/package/ncdu/Config.in
@@ -1,5 +1,6 @@
 config BR2_PACKAGE_NCDU
 	bool "ncdu"
+	depends on BR2_USE_MMU # system()
 	select BR2_PACKAGE_NCURSES
 	help
 	  ncdu is a disk usage analyzer with an ncurses interface