diff --git a/src/utils/getFilenameFromUrl.js b/src/utils/getFilenameFromUrl.js
index 82a58115a..4ebaa9a5f 100644
--- a/src/utils/getFilenameFromUrl.js
+++ b/src/utils/getFilenameFromUrl.js
@@ -10,12 +10,14 @@ const getPaths = require("./getPaths");
 const cacheStore = new WeakMap();
 
 /**
+ * @template T
  * @param {Function} fn
- * @param {{ cache?: Map<any, any> }} [cache]
+ * @param {{ cache?: Map<string, { data: T }> } | undefined} cache
+ * @param {(value: T) => T} callback
  * @returns {any}
  */
 // @ts-ignore
-const mem = (fn, { cache = new Map() } = {}) => {
+const mem = (fn, { cache = new Map() } = {}, callback) => {
   /**
    * @param {any} arguments_
    * @return {any}
@@ -28,7 +30,8 @@ const mem = (fn, { cache = new Map() } = {}) => {
       return cacheItem.data;
     }
 
-    const result = fn.apply(this, arguments_);
+    let result = fn.apply(this, arguments_);
+    result = callback(result);
 
     cache.set(key, {
       data: result,
@@ -41,7 +44,15 @@ const mem = (fn, { cache = new Map() } = {}) => {
 
   return memoized;
 };
-const memoizedParse = mem(parse);
+// eslint-disable-next-line no-undefined
+const memoizedParse = mem(parse, undefined, (value) => {
+  if (value.pathname) {
+    // eslint-disable-next-line no-param-reassign
+    value.pathname = decode(value.pathname);
+  }
+
+  return value;
+});
 
 const UP_PATH_REGEXP = /(?:^|[\\/])\.\.(?:[\\/]|$)/;
 
@@ -77,7 +88,9 @@ function getFilenameFromUrl(context, url, extra = {}) {
   const { options } = context;
   const paths = getPaths(context);
 
+  /** @type {string | undefined} */
   let foundFilename;
+  /** @type {URL} */
   let urlObject;
 
   try {
@@ -88,7 +101,9 @@ function getFilenameFromUrl(context, url, extra = {}) {
   }
 
   for (const { publicPath, outputPath } of paths) {
+    /** @type {string | undefined} */
     let filename;
+    /** @type {URL} */
     let publicPathObject;
 
     try {
@@ -102,8 +117,8 @@ function getFilenameFromUrl(context, url, extra = {}) {
       continue;
     }
 
-    const pathname = decode(urlObject.pathname);
-    const publicPathPathname = decode(publicPathObject.pathname);
+    const { pathname } = urlObject;
+    const { pathname: publicPathPathname } = publicPathObject;
 
     if (pathname && pathname.startsWith(publicPathPathname)) {
       // Null byte(s)
diff --git a/test/middleware.test.js b/test/middleware.test.js
index 79288d0b5..ead7886fc 100644
--- a/test/middleware.test.js
+++ b/test/middleware.test.js
@@ -859,6 +859,39 @@ describe.each([
               },
             ],
           },
+          {
+            file: "windows.txt",
+            data: "windows.txt content",
+            urls: [
+              {
+                value: "windows.txt",
+                contentType: "text/plain; charset=utf-8",
+                code: 200,
+              },
+            ],
+          },
+          {
+            file: "windows 2.txt",
+            data: "windows 2.txt content",
+            urls: [
+              {
+                value: "windows%202.txt",
+                contentType: "text/plain; charset=utf-8",
+                code: 200,
+              },
+            ],
+          },
+          {
+            file: "test & test & %20.txt",
+            data: "test & test & %20.txt content",
+            urls: [
+              {
+                value: "test%20%26%20test%20%26%20%2520.txt",
+                contentType: "text/plain; charset=utf-8",
+                code: 200,
+              },
+            ],
+          },
         ];
 
         const configurations = [
@@ -934,71 +967,28 @@ describe.each([
             },
             publicPathForRequest: "/",
           },
-        ];
-
-        const isWindows = process.platform === "win32";
-
-        if (isWindows) {
-          fixtures.push(
-            {
-              file: "windows.txt",
-              data: "windows.txt content",
-              urls: [
-                {
-                  value: "windows.txt",
-                  contentType: "text/plain; charset=utf-8",
-                  code: 200,
-                },
-              ],
-            },
-            {
-              file: "windows 2.txt",
-              data: "windows 2.txt content",
-              urls: [
-                {
-                  value: "windows%202.txt",
-                  contentType: "text/plain; charset=utf-8",
-                  code: 200,
-                },
-              ],
-            },
-            {
-              file: "test & test & %20.txt",
-              data: "test & test & %20.txt content",
-              urls: [
-                {
-                  value: "test%20%26%20test%20%26%20%2520.txt",
-                  contentType: "text/plain; charset=utf-8",
-                  code: 200,
-                },
-              ],
-            },
-          );
-
-          configurations.push(
-            {
-              output: {
-                path: path.join(basicOutputPath, "my static"),
-                publicPath: "/static/",
-              },
-              publicPathForRequest: "/static/",
+          {
+            output: {
+              path: path.join(basicOutputPath, "my static"),
+              publicPath: "/static/",
             },
-            {
-              output: {
-                path: path.join(basicOutputPath, "my%20static"),
-                publicPath: "/static/",
-              },
-              publicPathForRequest: "/static/",
+            publicPathForRequest: "/static/",
+          },
+          {
+            output: {
+              path: path.join(basicOutputPath, "my%20static"),
+              publicPath: "/static/",
             },
-            {
-              output: {
-                path: path.join(basicOutputPath, "my %20 static"),
-                publicPath: "/my%20static/",
-              },
-              publicPathForRequest: "/my%20static/",
+            publicPathForRequest: "/static/",
+          },
+          {
+            output: {
+              path: path.join(basicOutputPath, "my %20 static"),
+              publicPath: "/my%20static/",
             },
-          );
-        }
+            publicPathForRequest: "/my%20static/",
+          },
+        ];
 
         for (const configuration of configurations) {
           // eslint-disable-next-line no-loop-func