diff --git a/Cargo.toml b/Cargo.toml
index 08ace2f..18f646c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,6 +18,6 @@ name = "bench"
 harness = false
 
 [dev-dependencies]
-quickcheck = "0.3"
-rand = "*"
-bencher = "*"
+quickcheck = "~0.3"
+rand = "~0.3.12"
+bencher = "~0.1.2"