diff --git a/flake.nix b/flake.nix
index d1bb3c8..5cc7e3c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -110,7 +110,12 @@
           buildPhase = ''
             export HOME=$TMPDIR
             mkdir -p .cargo
-            cp ${vendoredDeps}/config.toml .cargo/config.toml
+            cat > .cargo/config.toml <<EOF
+            [source.crates-io]
+            replace-with = "vendored-sources"
+            [source.vendored-sources]
+            directory = "${vendoredDeps}"
+            EOF
             cargo build --release --target wasm32-wasip1 --offline
           '';