diff --git a/.gitignore b/.gitignore
index 1052d7d8a..983986903 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,7 +4,9 @@
 /.tern-port
 /local
 /bin/_acorn.js
-/acorn/dist
+/acorn/dist/*
 /acorn-loose/dist
 /acorn-walk/dist
 /yarn.lock
+!/acorn/dist/acorn.d.ts
+!/acorn/dist/acorn.mjs.d.ts
\ No newline at end of file
diff --git a/acorn/dist/acorn.mjs.d.ts b/acorn/dist/acorn.mjs.d.ts
new file mode 100644
index 000000000..5f633595e
--- /dev/null
+++ b/acorn/dist/acorn.mjs.d.ts
@@ -0,0 +1,2 @@
+import * as acorn from "./acorn";
+export = acorn;
\ No newline at end of file