diff --git a/package/shadowsocks-libev/Config.in b/package/shadowsocks-libev/Config.in
index 56914e8e9d..f58abdbcb1 100644
--- a/package/shadowsocks-libev/Config.in
+++ b/package/shadowsocks-libev/Config.in
@@ -1,5 +1,7 @@
 config BR2_PACKAGE_SHADOWSOCKS_LIBEV
 	bool "shadowsocks-libev"
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4 # for libcork
+	depends on BR2_TOOLCHAIN_HAS_SYNC_8 || !BR2_ARCH_IS_64 # for libcork
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_C_ARES
@@ -14,5 +16,7 @@ config BR2_PACKAGE_SHADOWSOCKS_LIBEV
 	  https://github.com/shadowsocks/shadowsocks-libev
 
 comment "shadowsocks-libev needs a toolchain w/ threads"
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
+	depends on BR2_TOOLCHAIN_HAS_SYNC_8 || !BR2_ARCH_IS_64
 	depends on BR2_USE_MMU
 	depends on !BR2_TOOLCHAIN_HAS_THREADS