diff --git a/snix/Cargo.lock b/snix/Cargo.lock
index b1f7dbb1d..ad09cbbdb 100644
--- a/snix/Cargo.lock
+++ b/snix/Cargo.lock
@@ -4294,6 +4294,7 @@ dependencies = [
  "tokio",
  "tracing",
  "tracing-indicatif",
+ "url",
  "wu-manber",
 ]
 
diff --git a/snix/Cargo.nix b/snix/Cargo.nix
index d3c65be17..537f1e084 100644
--- a/snix/Cargo.nix
+++ b/snix/Cargo.nix
@@ -14114,6 +14114,10 @@ rec {
             name = "tracing-indicatif";
             packageId = "tracing-indicatif";
           }
+          {
+            name = "url";
+            packageId = "url";
+          }
           {
             name = "wu-manber";
             packageId = "wu-manber";
diff --git a/snix/cli/Cargo.toml b/snix/cli/Cargo.toml
index 4672a788e..2af880ff3 100644
--- a/snix/cli/Cargo.toml
+++ b/snix/cli/Cargo.toml
@@ -27,6 +27,7 @@ tracing-indicatif.workspace = true
 rustc-hash.workspace = true
 mimalloc.workspace = true
 wu-manber.workspace = true
+url.workspace = true
 
 [dev-dependencies]
 expect-test.workspace = true
diff --git a/snix/cli/src/args.rs b/snix/cli/src/args.rs
index 9ddc4bdec..bae585ee3 100644
--- a/snix/cli/src/args.rs
+++ b/snix/cli/src/args.rs
@@ -2,6 +2,7 @@ use std::path::PathBuf;
 
 use clap::Parser;
 use snix_store::utils::ServiceUrlsMemory;
+use url::Url;
 
 /// Provides a CLI interface to trigger evaluation using snix-eval.
 ///
@@ -79,6 +80,13 @@ pub struct Args {
     /// Snix does not read from these.
     #[clap(long)]
     pub drv_dumpdir: Option<PathBuf>,
+
+    /// A list of web servers used by builtins.fetchurl to obtain files by hash.
+    /// Given a hash algorithm ha and a base-16 hash h, Nix will try to download the file
+    /// from hashed-mirror/ha/h. This allows files to be downloaded even if they have
+    /// disappeared from their original URI.
+    #[clap(long, default_values_t = [Url::parse("https://tarballs.nixos.org/").unwrap()])]
+    pub hashed_mirrors: Vec<Url>,
 }
 
 impl Args {
diff --git a/snix/cli/src/lib.rs b/snix/cli/src/lib.rs
index 2fdeeed3b..1c8035bd1 100644
--- a/snix/cli/src/lib.rs
+++ b/snix/cli/src/lib.rs
@@ -56,6 +56,7 @@ pub fn init_io_handle(tokio_runtime: &tokio::runtime::Runtime, args: &Args) -> R
         nar_calculation_service.into(),
         build_service.into(),
         tokio_runtime.handle().clone(),
+        args.hashed_mirrors.clone(),
     ))
 }
 
diff --git a/snix/glue/benches/eval.rs b/snix/glue/benches/eval.rs
index 03baa045b..d2a735b35 100644
--- a/snix/glue/benches/eval.rs
+++ b/snix/glue/benches/eval.rs
@@ -38,6 +38,7 @@ fn interpret(code: &str) {
         nar_calculation_service.into(),
         Arc::<DummyBuildService>::default(),
         TOKIO_RUNTIME.handle().clone(),
+        Vec::new(),
     ));
 
     let mut eval_builder = snix_eval::Evaluation::builder(Box::new(SnixIO::new(
diff --git a/snix/glue/src/builtins/mod.rs b/snix/glue/src/builtins/mod.rs
index e0a8155ec..6704d5bda 100644
--- a/snix/glue/src/builtins/mod.rs
+++ b/snix/glue/src/builtins/mod.rs
@@ -91,6 +91,7 @@ mod tests {
             nar_calculation_service.into(),
             Arc::<DummyBuildService>::default(),
             runtime.handle().clone(),
+            Vec::new(),
         ));
 
         let mut eval_builder = snix_eval::Evaluation::builder(io.clone() as Rc<dyn EvalIO>);
diff --git a/snix/glue/src/fetchers/mod.rs b/snix/glue/src/fetchers/mod.rs
index 0814a8efd..97a667c74 100644
--- a/snix/glue/src/fetchers/mod.rs
+++ b/snix/glue/src/fetchers/mod.rs
@@ -176,6 +176,7 @@ pub struct Fetcher<BS, DS, PS, NS> {
     directory_service: DS,
     path_info_service: PS,
     nar_calculation_service: NS,
+    _hashed_mirrors: Vec<Url>,
 }
 
 impl<BS, DS, PS, NS> Fetcher<BS, DS, PS, NS> {
@@ -184,6 +185,7 @@ impl<BS, DS, PS, NS> Fetcher<BS, DS, PS, NS> {
         directory_service: DS,
         path_info_service: PS,
         nar_calculation_service: NS,
+        hashed_mirrors: Vec<Url>,
     ) -> Self {
         Self {
             http_client: reqwest::Client::builder()
@@ -194,6 +196,7 @@ impl<BS, DS, PS, NS> Fetcher<BS, DS, PS, NS> {
             directory_service,
             path_info_service,
             nar_calculation_service,
+            _hashed_mirrors: hashed_mirrors,
         }
     }
 
diff --git a/snix/glue/src/snix_store_io.rs b/snix/glue/src/snix_store_io.rs
index 33f022b7d..85890d34d 100644
--- a/snix/glue/src/snix_store_io.rs
+++ b/snix/glue/src/snix_store_io.rs
@@ -13,6 +13,7 @@ use std::{
 use tokio_util::io::SyncIoBridge;
 use tracing::{Level, Span, error, instrument, warn};
 use tracing_indicatif::span_ext::IndicatifSpanExt;
+use url::Url;
 
 use snix_castore::{
     Node,
@@ -72,6 +73,7 @@ impl SnixStoreIO {
         nar_calculation_service: Arc<dyn NarCalculationService>,
         build_service: Arc<dyn BuildService>,
         tokio_handle: tokio::runtime::Handle,
+        hashed_mirrors: Vec<Url>,
     ) -> Self {
         Self {
             blob_service: blob_service.clone(),
@@ -86,6 +88,7 @@ impl SnixStoreIO {
                 directory_service,
                 path_info_service,
                 nar_calculation_service,
+                hashed_mirrors,
             ),
             known_paths: Default::default(),
         }
@@ -516,6 +519,7 @@ mod tests {
             nar_calculation_service.into(),
             Arc::<DummyBuildService>::default(),
             tokio_runtime.handle().clone(),
+            Vec::new(),
         ));
 
         let mut eval_builder =
diff --git a/snix/glue/src/tests/mod.rs b/snix/glue/src/tests/mod.rs
index fffacd648..d0f9b6e08 100644
--- a/snix/glue/src/tests/mod.rs
+++ b/snix/glue/src/tests/mod.rs
@@ -48,6 +48,7 @@ fn eval_test(code_path: PathBuf, expect_success: bool) {
         nar_calculation_service.into(),
         Arc::new(DummyBuildService::default()),
         tokio_runtime.handle().clone(),
+        Vec::new(),
     ));
     // Wrap with SnixIO, so <nix/fetchurl.nix can be imported.
     let mut eval_builder = snix_eval::Evaluation::builder(Box::new(SnixIO::new(