diff --git a/package/mdio-tools/Config.in b/package/mdio-tools/Config.in
index f24c1a6974..237f4454cc 100644
--- a/package/mdio-tools/Config.in
+++ b/package/mdio-tools/Config.in
@@ -1,12 +1,15 @@
 comment "mdio-tools needs a Linux kernel to be built"
+	depends on BR2_USE_MMU
 	depends on !BR2_LINUX_KERNEL
 
 comment "mdio-tools needs a toolchain w/ headers >= 5.1"
+	depends on BR2_USE_MMU
 	depends on BR2_LINUX_KERNEL
 	depends on !BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1
 
 config BR2_PACKAGE_MDIO_TOOLS
 	bool "mdio-tools"
+	depends on BR2_USE_MMU # fork()
 	depends on BR2_LINUX_KERNEL
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1
 	select BR2_PACKAGE_LIBMNL