diff --git a/build/lib/standalone.ts b/build/lib/standalone.ts
index 9813b4fd75e..b7b0fee295f 100644
--- a/build/lib/standalone.ts
+++ b/build/lib/standalone.ts
@@ -241,8 +241,8 @@ export function createESMSourcesAndResources2(options: IOptions2): void {
 		function toggleComments(fileContents: string): string {
 			let lines = fileContents.split(/\r\n|\r|\n/);
 			let mode = 0;
-			for (const line of lines) {
-
+			for (let i = 0; i < lines.length; i++) {
+				const line = lines[i];
 				if (mode === 0) {
 					if (/\/\/ ESM-comment-begin/.test(line)) {
 						mode = 1;
diff --git a/build/lib/treeshaking.ts b/build/lib/treeshaking.ts
index 223e8047c1f..060808312e6 100644
--- a/build/lib/treeshaking.ts
+++ b/build/lib/treeshaking.ts
@@ -464,7 +464,8 @@ function markNodes(languageService: ts.LanguageService, options: ITreeShakingOpt
 		}
 
 		if (black_queue.length === 0) {
-			for (const node of gray_queue) {
+			for (let i = 0; i< gray_queue.length; i++) {
+				const node = gray_queue[i];
 				const nodeParent = node.parent;
 				if ((ts.isClassDeclaration(nodeParent) || ts.isInterfaceDeclaration(nodeParent)) && nodeOrChildIsBlack(nodeParent)) {
 					gray_queue.splice(i, 1);