diff --git a/package/smstools3/Config.in b/package/smstools3/Config.in
index 72d0af6a8..1086869d8 100644
--- a/package/smstools3/Config.in
+++ b/package/smstools3/Config.in
@@ -1,5 +1,6 @@
 config BR2_PACKAGE_SMSTOOLS3
 	bool "smstools3"
+	depends on BR2_USE_MMU # fork()
 	depends on BR2_USE_WCHAR
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help