diff --git a/.npmignore b/.npmignore
index 5ab7afa..ebadcd6 100644
--- a/.npmignore
+++ b/.npmignore
@@ -19,6 +19,8 @@ dist
 /.projenrc.js
 tsconfig.tsbuildinfo
 /.eslintrc.json
+*.ts
+!*.d.ts
 /.gitattributes
 /.projenrc.ts
 /projenrc
diff --git a/.projenrc.ts b/.projenrc.ts
index 8ee03d3..c5ed436 100644
--- a/.projenrc.ts
+++ b/.projenrc.ts
@@ -74,6 +74,9 @@ const project = new typescript.TypeScriptProject({
   gitignore: ['**/*.d.ts', '**/*.js'],
 });
 
+project.addPackageIgnore('*.ts');
+project.addPackageIgnore('!*.d.ts');
+
 project.eslint?.addRules({
   'prettier/prettier': [
     'error',