diff --git a/.changeset/sweet-ties-wonder.md b/.changeset/sweet-ties-wonder.md
new file mode 100644
index 000000000000..3276ccd27a1d
--- /dev/null
+++ b/.changeset/sweet-ties-wonder.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-node': patch
+---
+
+fix: Enforce the calculated server directory is actually a directory (compatibility with bundlers)
diff --git a/packages/adapter-node/src/handler.js b/packages/adapter-node/src/handler.js
index 495f35db5236..d86a233b195b 100644
--- a/packages/adapter-node/src/handler.js
+++ b/packages/adapter-node/src/handler.js
@@ -21,7 +21,8 @@ const protocol_header = env('PROTOCOL_HEADER', '').toLowerCase();
 const host_header = env('HOST_HEADER', 'host').toLowerCase();
 const body_size_limit = parseInt(env('BODY_SIZE_LIMIT', '524288'));
 
-const dir = fileURLToPath(import.meta.SERVER_DIR);
+const root = fileURLToPath(import.meta.SERVER_DIR);
+const dir = !fs.statSync(root).isDirectory() ? path.dirname(root) : root;
 
 /**
  * @param {string} path