diff --git a/tsconfig.json b/tsconfig.json
index a990bb0534c..c7c3ca565f1 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,9 +1,9 @@
 {
     "compilerOptions": {
-        "target": "ES2020",
+        "target": "ES2015",
         "useDefineForClassFields": true,
         "module": "ESNext",
-        "lib": ["ES2020", "DOM", "DOM.Iterable"],
+        "lib": ["ES2015", "DOM", "DOM.Iterable"],
         "skipLibCheck": true,
 
         /* Bundler mode */