diff --git a/lib/make/mb_assert.mk b/lib/make/mb_assert.mk
index b948a32..61980d5 100644
--- a/lib/make/mb_assert.mk
+++ b/lib/make/mb_assert.mk
@@ -25,7 +25,7 @@ $(MB__RECIPE)$$(call mb_make_call,mb_os_dir_create,$(1)-test-$(2))
 $(MB__RECIPE)$$(call mb_make_call,mb_os_file_copy,$(1)/$(3).com,$(1)-test-$(2))
 $(MB__RECIPE)$$(call mb_make_call,mb_msxpipe_safe_test,$(1)-test-$(2),$(3) > $(3).out)
 $(MB__RECIPE)grep -q $(4) $(1)-test-$(2)/$(3).out
-$(MB__RECIPE)$$(call mb_make_call,mb_os_echo_assert,$$(MB_I18N_ASSERT_SUCCESS) FOO $(1)-test-$(2)/@assert)
+$(MB__RECIPE)$$(call mb_make_call,mb_os_echo_assert,$$(MB_I18N_ASSERT_SUCCESS) $(1)-test-$(2)/@assert)
 $(MB__　　　　)$$(call mb_make_call,mb_doc_target,$(1)-test-$(2)/@assert,"Asserts that $(3) output matches.")
 $(MB__　　　　)$$(call mb_make_call,mb_make_flag_phony,$(1)-test-$(2)/@assert)
 $(MB__　　　　)$$(call mb_make_call,mb_proj_grow_deps_phase_test,$(1)-test-$(2)/@assert)
diff --git a/lib/make/msxbuild.mk b/lib/make/msxbuild.mk
index d5dd805..241de48 100644
--- a/lib/make/msxbuild.mk
+++ b/lib/make/msxbuild.mk
@@ -28,7 +28,8 @@ include $(MB__BASEPATH)/lib/make/mb_tool.mk
 include $(MB__BASEPATH)/lib/make/mb_proj.mk
 include $(MB__BASEPATH)/lib/make/i18n/mb_i18n.mk
 ifneq ("$(MB_I18N)", "off")
--include $(MB__BASEPATH)/lib/make/i18n/mb_i18n_$(MB_I18N).mk
+$(if $(wildcard $(MB__BASEPATH)/lib/make/i18n/mb_i18n_$(MB_I18N).mk),,$(error Unsupported i18n language code: $(MB_I18N)))
+include $(MB__BASEPATH)/lib/make/i18n/mb_i18n_$(MB_I18N).mk
 endif