diff --git a/Cargo.toml b/Cargo.toml
index 46f8254b..050c62a0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,5 +7,5 @@ authors = ["Philipp Oppermann <dev@phil-opp.com>"]
 crate-type = ["staticlib"]
 
 [dependencies]
-rlibc = "*"
-spin = "*"
+rlibc = "0.1.4"
+spin = "0.3.4"
diff --git a/posts/2015-09-02-setup-rust.md b/posts/2015-09-02-setup-rust.md
index 318fb993..366c64f7 100644
--- a/posts/2015-09-02-setup-rust.md
+++ b/posts/2015-09-02-setup-rust.md
@@ -131,7 +131,7 @@ Fortunately there already is a crate for that: [rlibc]. When we look at its [sou
 ```toml
 ...
 [dependencies]
-rlibc = "*"
+rlibc = "0.1.4"
 ```
 and an `extern crate` definition in our `src/lib.rs`:
 
diff --git a/posts/2015-10-23-printing-to-screen.md b/posts/2015-10-23-printing-to-screen.md
index 90c7d8af..0989ebe2 100644
--- a/posts/2015-10-23-printing-to-screen.md
+++ b/posts/2015-10-23-printing-to-screen.md
@@ -315,8 +315,8 @@ To use a spinning mutex, we can add the [spin crate] as a dependency in Cargo.to
 ```toml
 ...
 [dependencies]
-rlibc = "*"
-spin = "*"
+rlibc = "0.1.4"
+spin = "0.3.4"
 ```
 and a `extern crate spin;` definition in `src/lib.rs`. Then we can use the spinning Mutex to provide interior mutability to our static writer: