diff --git a/flake.nix b/flake.nix
index 3f6a3dc..ad41bba 100644
--- a/flake.nix
+++ b/flake.nix
@@ -12,7 +12,16 @@
         "x86_64-darwin" "aarch64-darwin"
       ];
       forAllSystems = nixpkgs.lib.genAttrs stableSystems;
-      pkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+      # crates.io's WAF returns 403 for the default `curl/X.Y.Z` User-Agent.
+      fetchurlUserAgentOverlay = final: prev: {
+        fetchurl = args: prev.fetchurl (args // {
+          curlOptsList = (args.curlOptsList or []) ++ [ "-A" "logos-storage-nix" ];
+        });
+      };
+      pkgsFor = forAllSystems (system: import nixpkgs {
+        inherit system;
+        overlays = [ fetchurlUserAgentOverlay ];
+      });
     in
     {
       packages = forAllSystems (system: let