diff --git a/src/http_signatures.rs b/src/http_signatures.rs
index ca6a02f..c255f03 100644
--- a/src/http_signatures.rs
+++ b/src/http_signatures.rs
@@ -57,7 +57,7 @@ impl Keypair {
 ///
 /// Note that this method is very slow in debug mode. To make it faster, follow
 /// instructions in the RSA crate's readme.
-/// https://github.com/RustCrypto/RSA/blob/master/README.md
+/// <https://github.com/RustCrypto/RSA/blob/master/README.md>
 pub fn generate_actor_keypair() -> Result<Keypair, Error> {
     let mut rng = rand::thread_rng();
     let rsa = RsaPrivateKey::new(&mut rng, 2048)?;