diff --git a/packages/vite/src/runtime/moduleCache.ts b/packages/vite/src/runtime/moduleCache.ts
index 0b9aecd858bb19..3681e3db1ed78d 100644
--- a/packages/vite/src/runtime/moduleCache.ts
+++ b/packages/vite/src/runtime/moduleCache.ts
@@ -1,4 +1,4 @@
-import { isWindows, withTrailingSlash } from '../shared/utils'
+import { isWindows, slash, withTrailingSlash } from '../shared/utils'
 import { SOURCEMAPPING_URL } from '../shared/constants'
 import { decodeBase64 } from './utils'
 import { DecodedMap } from './sourcemap/decoder'
@@ -180,8 +180,7 @@ function normalizeModuleId(file: string, root: string): string {
   if (prefixedBuiltins.has(file)) return file
 
   // unix style, but Windows path still starts with the drive letter to check the root
-  let unixFile = file
-    .replace(/\\/g, '/')
+  let unixFile = slash(file)
     .replace(/^\/@fs\//, isWindows ? '' : '/')
     .replace(/^node:/, '')
     .replace(/^\/+/, '/')
diff --git a/packages/vite/src/runtime/runtime.ts b/packages/vite/src/runtime/runtime.ts
index 45132bf536b8b5..5feff38352617f 100644
--- a/packages/vite/src/runtime/runtime.ts
+++ b/packages/vite/src/runtime/runtime.ts
@@ -4,6 +4,7 @@ import {
   cleanUrl,
   isPrimitive,
   isWindows,
+  slash,
   unwrapId,
   wrapId,
 } from '../shared/utils'
@@ -164,7 +165,7 @@ export class ViteRuntime {
       // 8 is the length of "file:///"
       url = url.slice(isWindows ? 8 : 7)
     }
-    url = url.replace(/\\/g, '/')
+    url = slash(url)
     const _root = this.options.root
     const root = _root[_root.length - 1] === '/' ? _root : `${_root}/`
     // strip root from the URL because fetchModule prefers a public served url path
diff --git a/packages/vite/src/runtime/sourcemap/interceptor.ts b/packages/vite/src/runtime/sourcemap/interceptor.ts
index 5175c2d40a9a53..58d324e79b943c 100644
--- a/packages/vite/src/runtime/sourcemap/interceptor.ts
+++ b/packages/vite/src/runtime/sourcemap/interceptor.ts
@@ -2,6 +2,7 @@ import type { OriginalMapping } from '@jridgewell/trace-mapping'
 import type { ViteRuntime } from '../runtime'
 import { posixDirname, posixResolve } from '../utils'
 import type { ModuleCacheMap } from '../moduleCache'
+import { slash } from '../../shared/utils'
 import { DecodedMap, getOriginalPosition } from './decoder'
 
 interface RetrieveFileHandler {
@@ -88,24 +89,21 @@ interface CachedMapEntry {
 // Support URLs relative to a directory, but be careful about a protocol prefix
 function supportRelativeURL(file: string, url: string) {
   if (!file) return url
-  const dir = posixDirname(file.replace(/\\/g, '/'))
+  const dir = posixDirname(slash(file))
   const match = /^\w+:\/\/[^/]*/.exec(dir)
   let protocol = match ? match[0] : ''
   const startPath = dir.slice(protocol.length)
   if (protocol && /^\/\w:/.test(startPath)) {
     // handle file:///C:/ paths
     protocol += '/'
-    return (
-      protocol +
-      posixResolve(dir.slice(protocol.length), url).replace(/\\/g, '/')
-    )
+    return protocol + slash(posixResolve(startPath, url))
   }
-  return protocol + posixResolve(dir.slice(protocol.length), url)
+  return protocol + posixResolve(startPath, url)
 }
 
 function getRuntimeSourceMap(position: OriginalMapping): CachedMapEntry | null {
   for (const moduleCache of moduleGraphs) {
-    const sourceMap = moduleCache.getSourceMap(position.source as string)
+    const sourceMap = moduleCache.getSourceMap(position.source!)
     if (sourceMap) {
       return {
         url: position.source,