diff --git a/src/main.rs b/src/main.rs
index 819460a..51c3134 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,16 @@
 #![feature(let_chains)]
 
 use std::path::Path;
-use std::process::Command;
 use std::sync::mpsc;
 use std::sync::{
-    Arc, Mutex,
+    Arc, Mutex, RwLock,
     atomic::{AtomicUsize, Ordering},
 };
 
 use clap::Parser;
 use log::{debug, trace};
 use serde::{Deserialize, Serialize};
+use tokio::process::Command;
 use tokio::sync::Semaphore;
 
 const UPSTREAM_CACHES: &[&str] = &["https://cache.nixos.org"];
@@ -30,13 +30,15 @@ struct PathInfo {
 
 impl PathInfo {
     // find derivations related to package
-    fn from_package(package: &str) -> Vec<Self> {
+    async fn from_package(package: &str) -> Vec<Self> {
         let path_infos = Command::new("nix")
             .arg("path-info")
             .arg("--derivation")
+            .arg("--recursive")
             .arg("--json")
             .arg(package)
             .output()
+            .await
             .expect("path-info failed");
 
         let path_infos: Vec<PathInfo> = serde_json::from_slice(&path_infos.stdout).unwrap();
@@ -45,7 +47,7 @@ impl PathInfo {
     }
 
     // find store paths related to derivation
-    fn get_store_paths(&self) -> Vec<String> {
+    async fn get_store_paths(&self) -> Vec<String> {
         let mut store_paths: Vec<String> = Vec::new();
         let nix_store_cmd = Command::new("nix-store")
             .arg("--query")
@@ -53,6 +55,7 @@ impl PathInfo {
             .arg("--include-outputs")
             .arg(&self.path)
             .output()
+            .await
             .expect("nix-store cmd failed");
 
         let nix_store_out = String::from_utf8(nix_store_cmd.stdout).unwrap();
@@ -85,6 +88,10 @@ struct Cli {
     /// Concurrent uploaders
     #[arg(long, default_value_t = 10)]
     uploader_concurrency: u8,
+
+    /// Concurrent nix-store commands to run
+    #[arg(long, default_value_t = 50)]
+    nix_store_concurrency: u8,
 }
 
 #[tokio::main]
@@ -102,15 +109,33 @@ async fn main() {
     debug!("upstream caches: {:#?}", upstream_caches);
 
     println!("querying nix path-info");
-    let path_infos = PathInfo::from_package(package);
+    let derivations = PathInfo::from_package(package).await;
+    println!("got {} derivations", derivations.len());
 
     println!("querying nix-store");
-    let store_paths = path_infos[0].get_store_paths();
+    let mut handles = Vec::new();
+    let concurrency = Arc::new(Semaphore::new(cli.nix_store_concurrency.into()));
+    let store_paths = Arc::new(RwLock::new(Vec::new()));
+
+    for derivation in derivations {
+        let store_paths = Arc::clone(&store_paths);
+        let permit = Arc::clone(&concurrency);
+        handles.push(tokio::spawn(async move {
+            let _permit = permit.acquire_owned().await.unwrap();
+            let paths = derivation.get_store_paths().await;
+            store_paths.write().unwrap().extend(paths);
+        }));
+    }
+    // resolve store paths for all derivations before we move on
+    for handle in handles {
+        handle.await.unwrap();
+    }
+    println!("got {} store paths", store_paths.read().unwrap().len());
+
     let (cacheable_tx, cacheable_rx) = mpsc::channel();
 
-    let mut handles = Vec::new();
-
     println!("spawning check_upstream");
+    handles = Vec::new();
     handles.push(tokio::spawn(async move {
         check_upstream(
             store_paths,
@@ -134,19 +159,22 @@ async fn main() {
 
 // filter out store paths that exist in upstream caches
 async fn check_upstream(
-    store_paths: Vec<String>,
+    store_paths: Arc<RwLock<Vec<String>>>,
     cacheable_tx: mpsc::Sender<String>,
     concurrency: u8,
     upstream_caches: Arc<Vec<String>>,
 ) {
-    let concurrent = Semaphore::new(concurrency.into());
+    let concurrency = Arc::new(Semaphore::new(concurrency.into()));
+    let c_store_paths = Arc::clone(&store_paths);
+    let store_paths = c_store_paths.read().unwrap().clone();
 
     for store_path in store_paths {
-        let _ = concurrent.acquire().await.unwrap();
         let tx = cacheable_tx.clone();
         let upstream_caches = Arc::clone(&upstream_caches);
+        let concurrency = Arc::clone(&concurrency);
 
         tokio::spawn(async move {
+            let _permit = concurrency.acquire().await.unwrap();
             let basename = Path::new(&store_path)
                 .file_name()
                 .unwrap()
@@ -185,16 +213,18 @@ async fn check_upstream(
 async fn uploader(cacheable_rx: mpsc::Receiver<String>, binary_cache: String, concurrency: u8) {
     let upload_count = Arc::new(AtomicUsize::new(0));
     let failures: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
-    let concurrent = Semaphore::new(concurrency.into());
+    let concurrency = Arc::new(Semaphore::new(concurrency.into()));
     let mut handles = Vec::new();
+
     loop {
         if let Ok(path_to_upload) = cacheable_rx.recv() {
-            let _ = concurrent.acquire().await.unwrap();
+            let concurrency = Arc::clone(&concurrency);
             let failures = Arc::clone(&failures);
             let binary_cache = binary_cache.clone();
             let upload_count = Arc::clone(&upload_count);
 
             handles.push(tokio::spawn(async move {
+                let _permit = concurrency.acquire().await.unwrap();
                 println!("uploading: {}", path_to_upload);
                 if Command::new("nix")
                     .arg("copy")
@@ -202,6 +232,7 @@ async fn uploader(cacheable_rx: mpsc::Receiver<String>, binary_cache: String, co
                     .arg(&binary_cache)
                     .arg(&path_to_upload)
                     .output()
+                    .await
                     .is_err()
                 {
                     println!("WARN: upload failed: {}", path_to_upload);