diff --git a/tsconfig.json b/tsconfig.json
index 0323388..0fe82a5 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,10 +4,11 @@
     "sourceMap": true,
     "declaration": true,
     "declarationMap": true,
-    "target": "ES2017",
+    "target": "es5",
     "esModuleInterop": true,
     "strict": true,
     "experimentalDecorators": true,
+    "downlevelIteration": true,
     "moduleResolution": "Node",
     "module": "es6",
     "composite": true,