diff --git a/packages/playground/ssr-html/server.js b/packages/playground/ssr-html/server.js
index ad115f1be01163..1f2cd5331c0157 100644
--- a/packages/playground/ssr-html/server.js
+++ b/packages/playground/ssr-html/server.js
@@ -14,6 +14,14 @@ const DYNAMIC_SCRIPTS = `
   <script type="module" src="/src/app.js"></script>
 `
 
+const DYNAMIC_STYLES = `
+  <style>
+  h1 {
+    background-color: blue;
+  }
+  </style>
+`
+
 async function createServer(
   root = process.cwd(),
   isProd = process.env.NODE_ENV === 'production'
@@ -42,15 +50,30 @@ async function createServer(
   // use vite's connect instance as middleware
   app.use(vite.middlewares)
 
-  app.use('*', async (req, res) => {
+  app.use('*', async (req, res, next) => {
     try {
       let [url] = req.originalUrl.split('?')
       if (url.endsWith('/')) url += 'index.html'
 
+      if (url.startsWith('/favicon.ico')) {
+        return res.status(404).end('404')
+      }
+      if (url.startsWith('/@id/__x00__')) {
+        return next()
+      }
+
       const htmlLoc = resolve(`.${url}`)
-      let html = fs.readFileSync(htmlLoc, 'utf8')
-      html = html.replace('</body>', `${DYNAMIC_SCRIPTS}</body>`)
-      html = await vite.transformIndexHtml(url, html)
+      let template = fs.readFileSync(htmlLoc, 'utf-8')
+
+      template = template.replace(
+        '</body>',
+        `${DYNAMIC_SCRIPTS}${DYNAMIC_STYLES}</body>`
+      )
+
+      // Force calling transformIndexHtml with url === '/', to simulate
+      // usage by ecosystem that was recommended in the SSR documentation
+      // as `const url = req.originalUrl`
+      const html = await vite.transformIndexHtml('/', template)
 
       res.status(200).set({ 'Content-Type': 'text/html' }).end(html)
     } catch (e) {
diff --git a/packages/vite/src/node/server/middlewares/indexHtml.ts b/packages/vite/src/node/server/middlewares/indexHtml.ts
index 8638492b1c2001..955ee6b708f54d 100644
--- a/packages/vite/src/node/server/middlewares/indexHtml.ts
+++ b/packages/vite/src/node/server/middlewares/indexHtml.ts
@@ -1,6 +1,7 @@
 import fs from 'fs'
 import path from 'path'
 import MagicString from 'magic-string'
+import type { SourceMapInput } from 'rollup'
 import type { AttributeNode, ElementNode, TextNode } from '@vue/compiler-dom'
 import { NodeTypes } from '@vue/compiler-dom'
 import type { Connect } from 'types/connect'
@@ -15,7 +16,12 @@ import {
 } from '../../plugins/html'
 import type { ResolvedConfig, ViteDevServer } from '../..'
 import { send } from '../send'
-import { CLIENT_PUBLIC_PATH, FS_PREFIX } from '../../constants'
+import {
+  CLIENT_PUBLIC_PATH,
+  FS_PREFIX,
+  VALID_ID_PREFIX,
+  NULL_BYTE_PLACEHOLDER
+} from '../../constants'
 import {
   cleanUrl,
   fsPathFromId,
@@ -108,32 +114,53 @@ const devHtmlHook: IndexHtmlTransformHook = async (
   const { config, moduleGraph, watcher } = server!
   const base = config.base || '/'
 
+  let proxyModulePath: string
+  let proxyModuleUrl: string
+
+  const trailingSlash = htmlPath.endsWith('/')
+  if (!trailingSlash && fs.existsSync(filename)) {
+    proxyModulePath = htmlPath
+    proxyModuleUrl = base + htmlPath.slice(1)
+  } else {
+    // There are users of vite.transformIndexHtml calling it with url '/'
+    // for SSR integrations #7993, filename is root for this case
+    // A user may also use a valid name for a virtual html file
+    // Mark the path as virtual in both cases so sourcemaps aren't processed
+    // and ids are properly handled
+    const validPath = `${htmlPath}${trailingSlash ? 'index.html' : ''}`
+    proxyModulePath = `\0${validPath}`
+    proxyModuleUrl = `${VALID_ID_PREFIX}${NULL_BYTE_PLACEHOLDER}${validPath}`
+  }
+
   const s = new MagicString(html)
   let inlineModuleIndex = -1
-  const filePath = cleanUrl(htmlPath)
+  const proxyCacheUrl = cleanUrl(proxyModulePath).replace(
+    normalizePath(config.root),
+    ''
+  )
   const styleUrl: AssetNode[] = []
 
   const addInlineModule = (node: ElementNode, ext: 'js') => {
     inlineModuleIndex++
 
-    const url = filePath.replace(normalizePath(config.root), '')
-
     const contentNode = node.children[0] as TextNode
 
     const code = contentNode.content
-    const map = new MagicString(html)
-      .snip(contentNode.loc.start.offset, contentNode.loc.end.offset)
-      .generateMap({ hires: true })
-    map.sources = [filename]
-    map.file = filename
+
+    let map: SourceMapInput | undefined
+    if (!proxyModulePath.startsWith('\0')) {
+      map = new MagicString(html)
+        .snip(contentNode.loc.start.offset, contentNode.loc.end.offset)
+        .generateMap({ hires: true })
+      map.sources = [filename]
+      map.file = filename
+    }
 
     // add HTML Proxy to Map
-    addToHTMLProxyCache(config, url, inlineModuleIndex, { code, map })
+    addToHTMLProxyCache(config, proxyCacheUrl, inlineModuleIndex, { code, map })
 
     // inline js module. convert to src="proxy"
-    const modulePath = `${
-      config.base + htmlPath.slice(1)
-    }?html-proxy&index=${inlineModuleIndex}.${ext}`
+    const modulePath = `${proxyModuleUrl}?html-proxy&index=${inlineModuleIndex}.${ext}`
 
     // invalidate the module so the newly cached contents will be served
     const module = server?.moduleGraph.getModuleById(modulePath)
@@ -190,13 +217,13 @@ const devHtmlHook: IndexHtmlTransformHook = async (
 
   await Promise.all(
     styleUrl.map(async ({ start, end, code }, index) => {
-      const url = filename + `?html-proxy&${index}.css`
+      const url = `${proxyModulePath}?html-proxy&index=${index}.css`
 
       // ensure module in graph after successful load
       const mod = await moduleGraph.ensureEntryFromUrl(url, false)
       ensureWatchedFile(watcher, mod.file, config.root)
 
-      const result = await server!.pluginContainer.transform(code, url)
+      const result = await server!.pluginContainer.transform(code, mod.id!)
       s.overwrite(start, end, result?.code || '')
     })
   )