diff --git a/package/openntpd/Config.in b/package/openntpd/Config.in
index 32d0d8b06f..4dd9a297d5 100644
--- a/package/openntpd/Config.in
+++ b/package/openntpd/Config.in
@@ -1,5 +1,7 @@
 config BR2_PACKAGE_OPENNTPD
 	bool "openntpd"
+	# fork()
+	depends on BR2_USE_MMU
 	help
 	  OpenNTPD is an easy to use implementation of the Network Time
 	  Protocol. It provides the ability to sync the local clock