diff --git a/src/lean.rs b/src/lean.rs
new file mode 100644
index 0000000..498d5c4
--- /dev/null
+++ b/src/lean.rs
@@ -0,0 +1 @@
+pub mod elan;
diff --git a/src/lean/elan.rs b/src/lean/elan.rs
new file mode 100644
index 0000000..8b45b8d
--- /dev/null
+++ b/src/lean/elan.rs
@@ -0,0 +1,9 @@
+use structopt::StructOpt;
+
+#[derive(Debug, StructOpt)]
+pub struct ElanConfig {
+    #[structopt(long, default_value = "3")]
+    pub retain_elan_versions: usize,
+    #[structopt(long, default_value = "30")]
+    pub retain_lean_versions: usize,
+}
diff --git a/src/main.rs b/src/main.rs
index 751ae29..04a2ce5 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -32,6 +32,7 @@ mod html_scanner;
 mod index_pipe;
 #[macro_use]
 mod merge_pipe;
+mod lean;
 mod metadata;
 mod opts;
 mod pypi;
@@ -226,7 +227,7 @@ fn main() {
                 let script_src = rewrite_pipe::RewritePipe::new(
                     stream_pipe::ByteStreamPipe::new(
                         source.get_script(),
-                        buffer_path.clone().unwrap(),
+                        buffer_path.clone().expect("buffer path is not present"),
                         false,
                     ),
                     buffer_path.clone().unwrap(),
@@ -321,6 +322,36 @@ fn main() {
                     index_bytes_pipe!(buffer_path, prefix, false, 999)
                 );
             }
+            Source::Elan(source) => {
+                let elan_src = stream_pipe::ByteStreamPipe::new(
+                    GitHubRelease::new(
+                        String::from("leanprover/elan"),
+                        source.retain_elan_versions,
+                    ),
+                    buffer_path.clone().unwrap(),
+                    true,
+                );
+                let lean_src = stream_pipe::ByteStreamPipe::new(
+                    GitHubRelease::new(
+                        String::from("leanprover/lean4"),
+                        source.retain_lean_versions,
+                    ),
+                    buffer_path.clone().unwrap(),
+                    true,
+                );
+                let unified = merge_pipe! {
+                    elan: elan_src,
+                    lean: lean_src,
+                };
+                let indexed = index_pipe::IndexPipe::new(
+                    unified,
+                    buffer_path.clone().unwrap(),
+                    prefix.clone().unwrap(),
+                    999,
+                );
+
+                transfer!(opts, indexed, transfer_config, id_pipe!());
+            }
         }
     });
 }
diff --git a/src/opts.rs b/src/opts.rs
index 64771f3..f24f017 100644
--- a/src/opts.rs
+++ b/src/opts.rs
@@ -6,6 +6,7 @@ use crate::ghcup::Ghcup as GhcupConfig;
 use crate::github_release::GitHubRelease;
 use crate::gradle::Gradle;
 use crate::homebrew::HomebrewConfig;
+use crate::lean::elan::ElanConfig;
 use crate::pypi::Pypi as PypiConfig;
 use crate::rsync::Rsync as RsyncConfig;
 use crate::rustup::Rustup as RustupConfig;
@@ -37,6 +38,8 @@ pub enum Source {
     Gradle(Gradle),
     #[structopt(about = "rustup")]
     Rustup(RustupConfig),
+    #[structopt(about = "elan")]
+    Elan(ElanConfig),
 }
 
 #[derive(Debug)]
diff --git a/src/pypi.rs b/src/pypi.rs
index 4e853ed..a799779 100644
--- a/src/pypi.rs
+++ b/src/pypi.rs
@@ -193,7 +193,7 @@ async fn bigquery_index(logger: &Logger) -> Result<Vec<String>> {
 
 fn version_from_filename(filename: &str) -> Option<Version> {
     static RE_VERSION: once_cell::sync::Lazy<Regex> = once_cell::sync::Lazy::new(|| {
-        Regex::new(r#"^\w+-([\w.-_+]+).*(.tar.gz|tar.bz2|.zip|.whl|.exe|.egg)$"#).unwrap()
+        Regex::new(r"^\w+-([\w.-_+]+).*(.tar.gz|tar.bz2|.zip|.whl|.exe|.egg)$").unwrap()
     });
     RE_VERSION
         .captures(filename)