diff --git a/tvix/glue/src/fetchers/mod.rs b/tvix/glue/src/fetchers/mod.rs
index 4b53d0fda..2dbb7498b 100644
--- a/tvix/glue/src/fetchers/mod.rs
+++ b/tvix/glue/src/fetchers/mod.rs
@@ -31,7 +31,8 @@ pub enum Fetch {
     URL(Url, Option<NixHash>),
 
     /// Fetch a tarball from the given URL and unpack.
-    /// The file must be a tape archive (.tar) compressed with gzip, bzip2 or xz.
+    /// The file must be a tape archive (.tar), optionally compressed with gzip,
+    /// bzip2 or xz.
     /// The top-level path component of the files in the tarball is removed,
     /// so it is best if the tarball contains a single directory at top level.
     /// Optionally, a sha256 digest can be provided to verify the unpacked