diff --git a/.github/workflows/test_ebook_search.yml b/.github/workflows/test_ebook_search.yml
index 0e43e3e..823adfa 100644
--- a/.github/workflows/test_ebook_search.yml
+++ b/.github/workflows/test_ebook_search.yml
@@ -19,6 +19,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install dependencies
-        run: uv sync --locked --project python/ebook_search/docker
+        run: nix develop .#devShells.x86_64-linux.ebook-search -c uv sync --locked --project python/ebook_search/docker
       - name: Run ebook search tests
-        run: uv run --project python/ebook_search/docker --no-sync pytest tests/ebook_search --override-ini addopts="-n auto -ra"
+        run: nix develop .#devShells.x86_64-linux.ebook-search -c uv run --project python/ebook_search/docker --no-sync pytest tests/ebook_search --override-ini addopts="-n auto -ra"
diff --git a/shell.nix b/shell.nix
index b8a7742..13d40cb 100644
--- a/shell.nix
+++ b/shell.nix
@@ -3,6 +3,20 @@
   ...
 }:
 {
+  # For running the uv-managed ebook-search venv outside the container:
+  # PyPI manylinux wheels (numpy via bm25s) expect libstdc++.so.6 on the
+  # loader path, which NixOS does not provide globally.
+  ebook-search = pkgs.mkShell {
+    nativeBuildInputs = with pkgs; [
+      my_python
+      uv
+    ];
+    LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath [
+      pkgs.stdenv.cc.cc.lib
+      pkgs.zlib
+    ];
+  };
+
   default = pkgs.mkShell {
     NIX_CONFIG = "extra-experimental-features = nix-command flakes ca-derivations";
     nativeBuildInputs = with pkgs; [