diff --git a/lib/FunctionModuleTemplatePlugin.js b/lib/FunctionModuleTemplatePlugin.js
index 4f3ab6aab..5923f1865 100644
--- a/lib/FunctionModuleTemplatePlugin.js
+++ b/lib/FunctionModuleTemplatePlugin.js
@@ -11,6 +11,22 @@ const Template = require("./Template");
 
 /** @typedef {import("./ModuleTemplate")} ModuleTemplate */
 
+const joinIterableWithComma = iterable => {
+	// This is more performant than Array.from().join(", ")
+	// as it doesn't create an array
+	let str = "";
+	let first = true;
+	for (const item of iterable) {
+		str += item;
+		if (first) {
+			first = false;
+		} else {
+			str += ", ";
+		}
+	}
+	return str;
+};
+
 class FunctionModuleTemplatePlugin {
 	constructor({ compilation }) {
 		this.compilation = compilation;
@@ -62,9 +78,11 @@ class FunctionModuleTemplatePlugin {
 					const req = module.readableIdentifier(
 						moduleTemplate.runtimeTemplate.requestShortener
 					);
-					source.add("/*!****" + req.replace(/./g, "*") + "****!*\\\n");
-					source.add("  !*** " + req.replace(/\*\//g, "*_/") + " ***!\n");
-					source.add("  \\****" + req.replace(/./g, "*") + "****/\n");
+					const reqStr = req.replace(/\*\//g, "*_/");
+					const reqStrStar = "*".repeat(reqStr.length);
+					source.add("/*!****" + reqStrStar + "****!*\\\n");
+					source.add("  !*** " + reqStr + " ***!\n");
+					source.add("  \\****" + reqStrStar + "****/\n");
 					const providedExports = moduleGraph.getProvidedExports(module);
 					if (Array.isArray(providedExports)) {
 						if (providedExports.length === 0) {
@@ -81,9 +99,9 @@ class FunctionModuleTemplatePlugin {
 					}
 					source.add(
 						Template.toComment(
-							`runtime requirements: ${Array.from(
+							`runtime requirements: ${joinIterableWithComma(
 								chunkGraph.getModuleRuntimeRequirements(module)
-							).join(", ")}`
+							)}`
 						) + "\n"
 					);
 					const usedExports = moduleGraph.getUsedExports(module);
@@ -97,7 +115,7 @@ class FunctionModuleTemplatePlugin {
 						} else {
 							source.add(
 								Template.toComment(
-									"exports used: " + Array.from(usedExports).join(", ")
+									"exports used: " + joinIterableWithComma(usedExports)
 								) + "\n"
 							);
 						}