diff --git a/lib/util/deterministicGrouping.js b/lib/util/deterministicGrouping.js
index b30cc5cea..c6596f296 100644
--- a/lib/util/deterministicGrouping.js
+++ b/lib/util/deterministicGrouping.js
@@ -44,20 +44,30 @@ const similarity = (a, b) => {
 /**
  * @param {string} a key
  * @param {string} b key
+ * @param {Set<string>} usedNames set of already used names
  * @returns {string} the common part and a single char for the difference
  */
-const getName = (a, b) => {
+const getName = (a, b, usedNames) => {
 	const l = Math.min(a.length, b.length);
-	let r = "";
-	for (let i = 0; i < l; i++) {
-		const ca = a.charAt(i);
-		const cb = b.charAt(i);
-		r += ca;
-		if (ca === cb) {
-			continue;
+	let i = 0;
+	while (i < l) {
+		if (a.charCodeAt(i) !== b.charCodeAt(i)) {
+			i++;
+			break;
 		}
-		return r;
+		i++;
 	}
+	while (i < l) {
+		const name = a.slice(0, i);
+		const lowerName = name.toLowerCase();
+		if (!usedNames.has(lowerName)) {
+			usedNames.add(lowerName);
+			return name;
+		}
+		i++;
+	}
+	// names always contain a hash, so this is always unique
+	// we don't need to check usedNames nor add it
 	return a;
 };
 
@@ -391,12 +401,17 @@ module.exports = ({ maxSize, minSize, items, getSize, getKey }) => {
 	});
 
 	// give every group a name
+	const usedNames = new Set();
 	for (let i = 0; i < result.length; i++) {
 		const group = result[i];
-		const first = group.nodes[0];
-		const last = group.nodes[group.nodes.length - 1];
-		let name = getName(first.key, last.key);
-		group.key = name;
+		if (group.nodes.length === 1) {
+			group.key = group.nodes[0].key;
+		} else {
+			const first = group.nodes[0];
+			const last = group.nodes[group.nodes.length - 1];
+			const name = getName(first.key, last.key, usedNames);
+			group.key = name;
+		}
 	}
 
 	// return the results
diff --git a/test/configCases/split-chunks/max-size-casing/chunk.js b/test/configCases/split-chunks/max-size-casing/chunk.js
new file mode 100644
index 000000000..e3866c0c1
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/chunk.js
@@ -0,0 +1,9 @@
+import a from "./file-a1";
+import b from "./file-b1";
+import A from "./file-A2";
+import B from "./file-B2";
+export default "ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc" +
+	a +
+	b +
+	A +
+	B;
diff --git a/test/configCases/split-chunks/max-size-casing/file-A2.js b/test/configCases/split-chunks/max-size-casing/file-A2.js
new file mode 100644
index 000000000..befaa887e
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/file-A2.js
@@ -0,0 +1 @@
+export default "A2222222222222222222222";
diff --git a/test/configCases/split-chunks/max-size-casing/file-B2.js b/test/configCases/split-chunks/max-size-casing/file-B2.js
new file mode 100644
index 000000000..8f0106edc
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/file-B2.js
@@ -0,0 +1 @@
+export default "B2222222222222222222222";
diff --git a/test/configCases/split-chunks/max-size-casing/file-a1.js b/test/configCases/split-chunks/max-size-casing/file-a1.js
new file mode 100644
index 000000000..c0f085930
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/file-a1.js
@@ -0,0 +1 @@
+export default "a1111111111111111111111";
diff --git a/test/configCases/split-chunks/max-size-casing/file-b1.js b/test/configCases/split-chunks/max-size-casing/file-b1.js
new file mode 100644
index 000000000..6627122b6
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/file-b1.js
@@ -0,0 +1 @@
+export default "b1111111111111111111111";
diff --git a/test/configCases/split-chunks/max-size-casing/index.js b/test/configCases/split-chunks/max-size-casing/index.js
new file mode 100644
index 000000000..03c38ce45
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/index.js
@@ -0,0 +1,10 @@
+it("should ignore case insenstive chars when generating maxSize filenames", () =>
+	import(/* webpackChunkName: "chunk" */ "./chunk").then(
+		({ default: value }) => {
+			expect(value).toContain("a111");
+			expect(value).toContain("b111");
+			expect(value).toContain("A222");
+			expect(value).toContain("B222");
+			expect(value).toContain("cccc");
+		}
+	));
diff --git a/test/configCases/split-chunks/max-size-casing/test.config.js b/test/configCases/split-chunks/max-size-casing/test.config.js
new file mode 100644
index 000000000..2e3be0636
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/test.config.js
@@ -0,0 +1,5 @@
+module.exports = {
+	findBundle: function (i, options) {
+		return ["main.js"];
+	}
+};
diff --git a/test/configCases/split-chunks/max-size-casing/webpack.config.js b/test/configCases/split-chunks/max-size-casing/webpack.config.js
new file mode 100644
index 000000000..beebf1574
--- /dev/null
+++ b/test/configCases/split-chunks/max-size-casing/webpack.config.js
@@ -0,0 +1,14 @@
+/** @type {import("../../../../").Configuration} */
+module.exports = {
+	output: {
+		filename: "[name].js"
+	},
+	optimization: {
+		chunkIds: "named",
+		splitChunks: {
+			hidePathInfo: false,
+			minSize: 50,
+			maxSize: 100
+		}
+	}
+};