diff --git a/Cargo.toml b/Cargo.toml
index 4450162..4fe2043 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,5 +9,5 @@ rustc_version = "0.2"
 [dependencies]
 crunchy = "0.1.5"
 ethereum-types = { path ="../ethereum-types", features = ["std", "heapsizeof"] }
-quickcheck = "0.4"
+quickcheck = "0.6"
 uint = { path = "../uint" }