diff --git a/Cargo.toml b/Cargo.toml
index 21162b08..f7b4439f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,8 +13,8 @@ license = "MIT OR Apache-2.0"
 name = "api"
 
 [dependencies]
-rand = "0.3"
-rustc-serialize = "0.3"
+rand = "0.4"
+rustc-serialize = { git = "https://github.com/cdetrio/rustc-serialize", branch = "for-wasm" }
 byteorder = "1.0"
 
 [dev-dependencies.bincode]