diff --git a/package/gob2/Config.in b/package/gob2/Config.in
index 562ac3123c..cbe30d66d0 100644
--- a/package/gob2/Config.in
+++ b/package/gob2/Config.in
@@ -1,6 +1,8 @@
 config BR2_PACKAGE_GOB2
 	bool "gob2"
 	depends on BR2_USE_WCHAR # glib2
+	# m4 uses fork(), so does bison then
+	depends on BR2_USE_MMU
 	select BR2_PACKAGE_LIBGLIB2
 	select BR2_PACKAGE_FLEX
 	select BR2_PACKAGE_FLEX_LIBFL