diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 73210b303..556365375 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -27,7 +27,7 @@ Check out the [security policy](https://github.com/NixOS/nix/security/policy).
 1. Search for related issues that cover what you're going to work on.
    It could help to mention there that you will work on the issue.
 
-   Issues labeled [good first issue](https://github.com/NixOS/nix/labels/good-first-issue) should be relatively easy to fix and are likely to get merged quickly.
+   Issues labeled [good first issue](https://github.com/NixOS/nix/labels/good%20first%20issue) should be relatively easy to fix and are likely to get merged quickly.
    Pull requests addressing issues labeled [idea approved](https://github.com/NixOS/nix/labels/idea%20approved) or [RFC](https://github.com/NixOS/nix/labels/RFC) are especially welcomed by maintainers and will receive prioritised review.
 
    If there is no relevant issue yet and you're not sure whether your change is likely to be accepted, [open an issue](https://github.com/NixOS/nix/issues/new/choose) yourself.