diff --git a/code/core/src/cli/dirs.ts b/code/core/src/cli/dirs.ts
index 3529582b63be..54c47005b1c8 100644
--- a/code/core/src/cli/dirs.ts
+++ b/code/core/src/cli/dirs.ts
@@ -1,4 +1,4 @@
-import { join } from 'node:path';
+import { join, posix } from 'node:path';
 import { Readable } from 'node:stream';
 import { pipeline } from 'node:stream/promises';
 import type { ReadableStream } from 'node:stream/web';
@@ -53,7 +53,7 @@ export async function getRendererDir(
   const frameworkPackageName =
     externalFramework?.packageName || externalFramework?.renderer || `@storybook/${renderer}`;
 
-  const packageJsonPath = join(frameworkPackageName, 'package.json');
+  const packageJsonPath = posix.join(frameworkPackageName, 'package.json');
 
   const errors: Error[] = [];
 
diff --git a/code/core/src/core-server/build-dev.ts b/code/core/src/core-server/build-dev.ts
index 750920a0cc6f..832a44df9f57 100644
--- a/code/core/src/core-server/build-dev.ts
+++ b/code/core/src/core-server/build-dev.ts
@@ -1,5 +1,5 @@
 import { readFile } from 'node:fs/promises';
-import { join, relative, resolve } from 'node:path';
+import { join, posix, relative, resolve } from 'node:path';
 
 import {
   JsPackageManagerFactory,
@@ -115,7 +115,7 @@ export async function buildDevStandalone(
     validateFrameworkName(frameworkName);
   }
   if (frameworkName) {
-    corePresets.push(join(frameworkName, 'preset'));
+    corePresets.push(posix.join(frameworkName, 'preset'));
   }
 
   frameworkName = frameworkName || 'custom';
diff --git a/code/core/src/core-server/build-static.ts b/code/core/src/core-server/build-static.ts
index 96679b114bd4..7e17eb2a3fe8 100644
--- a/code/core/src/core-server/build-static.ts
+++ b/code/core/src/core-server/build-static.ts
@@ -1,6 +1,6 @@
 import { cp, mkdir } from 'node:fs/promises';
 import { rm } from 'node:fs/promises';
-import { join, relative, resolve } from 'node:path';
+import { join, posix, relative, resolve } from 'node:path';
 
 import {
   loadAllPresets,
@@ -56,7 +56,7 @@ export async function buildStaticStandalone(options: BuildStaticStandaloneOption
 
   const frameworkName = typeof framework === 'string' ? framework : framework?.name;
   if (frameworkName) {
-    corePresets.push(join(frameworkName, 'preset'));
+    corePresets.push(posix.join(frameworkName, 'preset'));
   } else if (!options.ignorePreview) {
     logger.warn(`you have not specified a framework in your ${options.configDir}/main.js`);
   }
diff --git a/code/core/src/core-server/load.ts b/code/core/src/core-server/load.ts
index baa453682605..e99167ae17b6 100644
--- a/code/core/src/core-server/load.ts
+++ b/code/core/src/core-server/load.ts
@@ -1,4 +1,4 @@
-import { join, relative, resolve } from 'node:path';
+import { join, posix, relative, resolve } from 'node:path';
 
 import {
   getProjectRoot,
@@ -39,7 +39,7 @@ export async function loadStorybook(
     validateFrameworkName(frameworkName);
   }
   if (frameworkName) {
-    corePresets.push(join(frameworkName, 'preset'));
+    corePresets.push(posix.join(frameworkName, 'preset'));
   }
 
   frameworkName = frameworkName || 'custom';