diff --git a/package/cppcms/Config.in b/package/cppcms/Config.in
index 2b99b521c8..418146a7fc 100644
--- a/package/cppcms/Config.in
+++ b/package/cppcms/Config.in
@@ -24,11 +24,18 @@ config BR2_PACKAGE_CPPCMS_ICU
 	bool "enable icu support"
 	depends on !BR2_arc # icu -> atomic builtins
 	depends on !BR2_BINFMT_FLAT # icu
+	depends on BR2_USE_WCHAR # icu
+	depends on BR2_TOOLCHAIN_HAS_THREADS # icu
 	select BR2_PACKAGE_ICU
 	help
 	  Using ICU allows advanced localization features into CppCMS,
 	  in another hand ICU is heavier than iconv.
 
+comment "icu support needs a toolchain w/ wchar, threads"
+	depends on !BR2_arc
+	depends on !BR2_BINFMT_FLAT
+	depends on !BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS
+
 endif
 
 comment "cppcms needs a toolchain w/ C++"