diff --git a/lib/manager/cargo/readme.md b/lib/manager/cargo/readme.md
index b5666e0cfe282c94ffe11aee230cfe0b6222950c..17cb185cf624815682e419a41b642e14a0b8edaf 100644
--- a/lib/manager/cargo/readme.md
+++ b/lib/manager/cargo/readme.md
@@ -147,7 +147,7 @@ setting version to =1.3.4
 
 #### Is a new datasource required? Provide details
 
-New crate versions can be fetched from [crates.io](crates.io).
+New crate versions can be fetched from [crates.io](https://crates.io).
 
 ---