diff --git a/flake.nix b/flake.nix
index b862e8e6..7d152195 100644
--- a/flake.nix
+++ b/flake.nix
@@ -9,7 +9,7 @@
   };
 
   outputs = { self, nixpkgs, cargo2nix }: let
-    git_version = "v0.8.0-rc2";
+    git_version = self.lastModifiedDate;
     compile = import ./nix/compile.nix;
     forAllSystems = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed;
   in
diff --git a/shell.nix b/shell.nix
index 5cece8ad..10058fc4 100644
--- a/shell.nix
+++ b/shell.nix
@@ -71,13 +71,25 @@ function refresh_cache {
   for attr in clippy.amd64 test.amd64 pkgs.{amd64,i386,arm,arm64}.{debug,release}; do
     echo "Updating cache for ''${attr}"
     derivation=$(nix-instantiate --attr ''${attr})
-    nix copy \
+    nix copy -j8 \
       --to 's3://nix?endpoint=garage.deuxfleurs.fr&region=garage&secret-key=/tmp/nix-signing-key.sec' \
       $(nix-store -qR ''${derivation%\!bin})
   done
   rm /tmp/nix-signing-key.sec
 }
 
+function refresh_flake_cache {
+  pass show deuxfleurs/nix_priv_key > /tmp/nix-signing-key.sec
+  for attr in packages.x86_64-linux.default; do
+    echo "Updating cache for ''${attr}"
+    derivation=$(nix path-info --derivation ".#''${attr}")
+    nix copy -j8 \
+      --to 's3://nix?endpoint=garage.deuxfleurs.fr&region=garage&secret-key=/tmp/nix-signing-key.sec' \
+      $(nix-store -qR ''${derivation})
+  done
+  rm /tmp/nix-signing-key.sec
+}
+
 function to_s3 {
   aws \
       --endpoint-url https://garage.deuxfleurs.fr \