diff --git a/marimo/_server/lsp.py b/marimo/_server/lsp.py
index 07ffb67deae..03863aff6f7 100644
--- a/marimo/_server/lsp.py
+++ b/marimo/_server/lsp.py
@@ -196,7 +196,7 @@ def get_command(self) -> list[str]:
             LOGGER.debug("LSP binary not found at %s", lsp_bin)
             return []
 
-        copilot_bin = self._lsp_dir() / "copilot" / "language-server.js"
+        copilot_bin = self._lsp_dir() / "copilot" / "language-server.cjs"
         log_file = _loggers.get_log_directory() / "github-copilot-lsp.log"
 
         # Use typed format to avoid quoting issues: copilot:<binary_path>
diff --git a/packages/lsp/move.js b/packages/lsp/move.js
new file mode 100644
index 00000000000..4011c6d735b
--- /dev/null
+++ b/packages/lsp/move.js
@@ -0,0 +1,22 @@
+#!/usr/bin/env node
+
+const fs = require("node:fs");
+const path = require("node:path");
+
+// Copy node_modules/@github/copilot-language-server/dist/ to dist/
+const srcDir = path.join(
+  __dirname,
+  "node_modules/@github/copilot-language-server/dist",
+);
+const destDir = path.join(__dirname, "dist");
+
+// Recursively copy directory
+fs.cpSync(srcDir, destDir, { recursive: true, dereference: true });
+
+// Rename language-server.js to language-server.cjs
+const oldPath = path.join(destDir, "language-server.js");
+const newPath = path.join(destDir, "language-server.cjs");
+fs.renameSync(oldPath, newPath);
+
+// biome-ignore lint/suspicious/noConsole: build script
+console.log("Successfully copied and renamed language-server files");
diff --git a/packages/lsp/package.json b/packages/lsp/package.json
index 0cecdf0e353..e42d4b0019d 100644
--- a/packages/lsp/package.json
+++ b/packages/lsp/package.json
@@ -5,7 +5,7 @@
   "license": "Apache-2.0",
   "scripts": {
     "build:ts": "tsup index.ts --format cjs --minify",
-    "build:deps": "cp -LR node_modules/@github/copilot-language-server/dist/ dist/",
+    "build:deps": "node move.js",
     "typecheck": "tsgo",
     "build": "pnpm run build:ts && pnpm run build:deps",
     "test": "vitest"
diff --git a/tests/_server/test_lsp.py b/tests/_server/test_lsp.py
index 43696c6a12b..fb39fdb916d 100644
--- a/tests/_server/test_lsp.py
+++ b/tests/_server/test_lsp.py
@@ -150,7 +150,7 @@ def test_copilot_server_uses_typed_format(tmp_path: Path) -> None:
 
     copilot_dir = lsp_dir_with_spaces / "copilot"
     copilot_dir.mkdir()
-    copilot_bin = copilot_dir / "language-server.js"
+    copilot_bin = copilot_dir / "language-server.cjs"
     copilot_bin.touch()
 
     # Mock the _lsp_dir method to return our test directory