diff --git a/src/path_info.rs b/src/path_info.rs
index 746c344..e67dc4a 100644
--- a/src/path_info.rs
+++ b/src/path_info.rs
@@ -2,8 +2,8 @@ use std::collections::HashSet;
 
 use anyhow::{Context, Error, Result};
 use log::{debug, error, trace};
-use nix_compat::nixhash::CAHash;
 use nix_compat::store_path::StorePath;
+use nix_compat::{nixbase32, nixhash::CAHash};
 use regex::Regex;
 use serde::{Deserialize, Serialize};
 use tokio::process::Command;
@@ -97,12 +97,9 @@ impl PathInfo {
     }
 
     pub async fn check_upstream_hit(&self, upstreams: &[Url]) -> bool {
-        let hash =
-            String::from_utf8(self.path.digest().to_vec()).expect("should be a valid string");
-
         for upstream in upstreams {
             let upstream = upstream
-                .join(format!("{hash}/.narinfo").as_str())
+                .join(format!("{}/.narinfo", self.digest()).as_str())
                 .expect("adding <hash>.narinfo should make a valid url");
             let res_status = reqwest::Client::new()
                 .head(upstream.as_str())
@@ -121,8 +118,8 @@ impl PathInfo {
         self.path.to_absolute_path()
     }
 
-    pub fn digest(&self) -> &str {
-        str::from_utf8(self.path.digest()).expect("digest should be valid string")
+    pub fn digest(&self) -> String {
+        nixbase32::encode(self.path.digest())
     }
 }
 
diff --git a/src/uploader.rs b/src/uploader.rs
index 81f4be8..90ce70b 100644
--- a/src/uploader.rs
+++ b/src/uploader.rs
@@ -49,8 +49,10 @@ impl<'a> Uploader<'a> {
         nar_info.file_size = Some(nar.len() as u64);
         let mut hasher = Sha256::new();
         hasher.update(&nar);
-        nar_info.file_hash = Some(hasher.finalize().into());
-        let nar_url = self.nar_url(&nar);
+        let hash: [u8; 32] = hasher.finalize().into();
+        let nar_url = self.nar_url(&hash);
+        nar_info.file_hash = Some(hash);
+        debug!("uploading to bucket with key: {nar_url}");
 
         if nar.len() < MULTIPART_CUTOFF {
             let put_object = self
@@ -120,8 +122,6 @@ impl<'a> Uploader<'a> {
             debug!("complete multipart upload: {:#?}", complete_mp_upload);
         }
 
-        nar_info.add_signature(self.signing_key);
-
         self.s3_client
             .put_object()
             .bucket(&self.bucket)
@@ -147,7 +147,7 @@ impl<'a> Uploader<'a> {
         let mut hasher = Sha256::new();
         hasher.update(nar);
         let nar_hash: [u8; 32] = hasher.finalize().into();
-        let nar_info = NarInfo {
+        let mut nar_info = NarInfo {
             flags: narinfo::Flags::empty(),
             store_path: self.path.path.as_ref(),
             nar_hash,
@@ -162,6 +162,8 @@ impl<'a> Uploader<'a> {
             file_size: None,
             url: "",
         };
+        // signature consists of: store_path, nar_hash, nar_size, and references
+        nar_info.add_signature(self.signing_key);
         Ok(nar_info)
     }