diff --git a/packages/vite-node/src/server.ts b/packages/vite-node/src/server.ts
index e1eb6f5a4563..cad850034238 100644
--- a/packages/vite-node/src/server.ts
+++ b/packages/vite-node/src/server.ts
@@ -1,6 +1,6 @@
 import { performance } from 'node:perf_hooks'
 import { existsSync } from 'node:fs'
-import { join, relative, resolve } from 'pathe'
+import { join, normalize, relative, resolve } from 'pathe'
 import type { TransformResult, ViteDevServer } from 'vite'
 import createDebug from 'debug'
 import type { EncodedSourceMap } from '@jridgewell/trace-mapping'
@@ -72,6 +72,18 @@ export class ViteNodeServer {
     const customModuleDirectories = envValue?.split(',')
     if (customModuleDirectories)
       options.deps.moduleDirectories.push(...customModuleDirectories)
+
+    options.deps.moduleDirectories = options.deps.moduleDirectories.map((dir) => {
+      if (!dir.startsWith('/'))
+        dir = `/${dir}`
+      if (!dir.endsWith('/'))
+        dir += '/'
+      return normalize(dir)
+    })
+
+    // always add node_modules as a module directory
+    if (!options.deps.moduleDirectories.includes('/node_modules/'))
+      options.deps.moduleDirectories.push('/node_modules/')
   }
 
   shouldExternalize(id: string) {
diff --git a/packages/vitest/src/node/config.ts b/packages/vitest/src/node/config.ts
index 947bdfc7d895..087076ac6375 100644
--- a/packages/vitest/src/node/config.ts
+++ b/packages/vitest/src/node/config.ts
@@ -140,7 +140,7 @@ export function resolveConfig(
       resolved.deps.inline.push(...extraInlineDeps)
     }
   }
-  resolved.deps.moduleDirectories ??= ['/node_modules/']
+  resolved.deps.moduleDirectories ??= []
   resolved.deps.moduleDirectories = resolved.deps.moduleDirectories.map((dir) => {
     if (!dir.startsWith('/'))
       dir = `/${dir}`
@@ -148,6 +148,8 @@ export function resolveConfig(
       dir += '/'
     return normalize(dir)
   })
+  if (!resolved.deps.moduleDirectories.includes('/node_modules/'))
+    resolved.deps.moduleDirectories.push('/node_modules/')
 
   if (resolved.runner) {
     resolved.runner = resolveModule(resolved.runner, { paths: [resolved.root] })