diff --git a/src/helpers.ts b/src/helpers.ts
index 1f659b7..21f3742 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -1,4 +1,3 @@
-import { FilterPattern, normalizePath } from "@rollup/pluginutils";
 import path from "path";
 import { OutputOptions } from "rollup";
 
@@ -25,16 +24,3 @@ export function getRelativeImportPath(from: string, to: string) {
 
 	return import_path;
 }
-
-export function normalizeFilterPattern(pattern?: FilterPattern): FilterPattern | undefined {
-	if (typeof pattern === "string") return normalizePath(pattern);
-
-	if (Array.isArray(pattern)) {
-		return pattern.map(element => {
-			if (typeof element === "string") return normalizePath(element);
-			return element;
-		});
-	}
-
-	return pattern;
-}
diff --git a/src/index.ts b/src/index.ts
index 94cf9a1..11c3bdf 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3,7 +3,7 @@ import path from "path";
 import { Plugin } from "rollup";
 import { createFilter, FilterPattern, normalizePath } from "@rollup/pluginutils";
 import { parse, print, types, visit } from "recast";
-import { getOutputId, getRelativeImportPath, normalizeFilterPattern } from "./helpers";
+import { getOutputId, getRelativeImportPath } from "./helpers";
 
 const PLUGIN_NAME = "external-assets";
 const PREFIX = `\0${PLUGIN_NAME}:`;
@@ -34,8 +34,6 @@ export default function externalAssets(
 	exclude?: FilterPattern,
 	options?: Options,
 ): Plugin {
-	include = normalizeFilterPattern(include);
-	exclude = normalizeFilterPattern(exclude);
 	const idFilter = createFilter(include, exclude, options);
 	const assets = new Map<string, Buffer>();
 
diff --git a/tests/unit.test.ts b/tests/unit.test.ts
index 9e91f5f..85a3313 100644
--- a/tests/unit.test.ts
+++ b/tests/unit.test.ts
@@ -1,5 +1,5 @@
 import path from "path";
-import { getOutputId, normalizeFilterPattern } from "../src/helpers";
+import { getOutputId } from "../src/helpers";
 
 test("getOutputId", () => {
 	expect(getOutputId("a.ext", { dir: "out" })).toBe(path.resolve("out/a.ext"));
@@ -12,23 +12,3 @@ test("getOutputId", () => {
 	expect(getOutputId("a.ext", {})).toBe(path.resolve("a.ext"));
 	expect(getOutputId("a/b.ext", {})).toBe(path.resolve("a/b.ext"));
 });
-
-test("normalizeFilterPattern", () => {
-	expect(normalizeFilterPattern()).toBeUndefined();
-	expect(normalizeFilterPattern(null)).toBeNull();
-	expect(normalizeFilterPattern(/\.txt/g)).toStrictEqual(/\.txt/g);
-	expect(normalizeFilterPattern("abc/def/**/*")).toBe("abc/def/**/*");
-	expect(normalizeFilterPattern("abc\\def\\**\\*")).toBe("abc/def/**/*");
-	expect(normalizeFilterPattern(path.resolve("abc/def/**/*"))).toBe(path.resolve("abc/def/**/*").replace(/\\/g, "/"));
-	expect([
-		normalizeFilterPattern(/\.txt/g),
-		normalizeFilterPattern("abc/def/**/*"),
-		normalizeFilterPattern("abc\\def\\**\\*"),
-		normalizeFilterPattern(path.resolve("abc/def/**/*")),
-	]).toStrictEqual([
-		/\.txt/g,
-		"abc/def/**/*",
-		"abc/def/**/*",
-		path.resolve("abc/def/**/*").replace(/\\/g, "/"),
-	]);
-});