diff --git a/package/libeXosip2/Config.in b/package/libeXosip2/Config.in
index 755d28461..3fe9c9697 100644
--- a/package/libeXosip2/Config.in
+++ b/package/libeXosip2/Config.in
@@ -1,5 +1,6 @@
 config BR2_PACKAGE_LIBEXOSIP2
 	bool "libeXosip2"
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_LIBOSIP2
 	help
 	  eXosip is a library that hides the complexity of using the
diff --git a/package/linphone/Config.in b/package/linphone/Config.in
index a2866a6fb..bd5141261 100644
--- a/package/linphone/Config.in
+++ b/package/linphone/Config.in
@@ -6,6 +6,7 @@ config BR2_PACKAGE_LINPHONE
 	select BR2_PACKAGE_MEDIASTREAMER
 	depends on BR2_INSTALL_LIBSTDCPP # mediastreamer
 	depends on BR2_TOOLCHAIN_HAS_THREADS # ortp
+	depends on BR2_USE_MMU # libeXosip2
 	help
 	  Linphone is an internet phone or Voice Over IP phone (VoIP).