diff --git a/tsconfig.esm.json b/tsconfig.esm.json
index bd44cbf..c1908c0 100644
--- a/tsconfig.esm.json
+++ b/tsconfig.esm.json
@@ -3,6 +3,6 @@
     "include": ["src/index.ts"],
     "compilerOptions": {
         "module": "es2015",
-        "outDir": "dist/zz_esm"
+        "outDir": "dist/zz_esm/"
     }
 }