diff --git a/packages/wxt/src/core/utils/__tests__/manifest.test.ts b/packages/wxt/src/core/utils/__tests__/manifest.test.ts
index b43faba8..c406a1d1 100644
--- a/packages/wxt/src/core/utils/__tests__/manifest.test.ts
+++ b/packages/wxt/src/core/utils/__tests__/manifest.test.ts
@@ -1503,7 +1503,7 @@ describe('Manifest Utils', () => {
         expect(actual).toMatchObject({
           content_security_policy:
             "script-src 'self' http://localhost:3000; object-src 'self';",
-          permissions: ['http://localhost:3000/*', 'tabs'],
+          permissions: ['http://localhost/*', 'tabs'],
         });
       });
 
@@ -1535,7 +1535,7 @@ describe('Manifest Utils', () => {
             sandbox:
               "script-src 'self' 'unsafe-inline' 'unsafe-eval' http://localhost:3000; sandbox allow-scripts allow-forms allow-popups allow-modals; child-src 'self';",
           },
-          host_permissions: ['http://localhost:3000/*'],
+          host_permissions: ['http://localhost/*'],
           permissions: ['tabs', 'scripting'],
         });
       });
diff --git a/packages/wxt/src/core/utils/manifest.ts b/packages/wxt/src/core/utils/manifest.ts
index 7b4682a5..2f0b4c90 100644
--- a/packages/wxt/src/core/utils/manifest.ts
+++ b/packages/wxt/src/core/utils/manifest.ts
@@ -459,7 +459,13 @@ function discoverIcons(
 }
 
 function addDevModeCsp(manifest: Browser.runtime.Manifest): void {
-  const permission = `${wxt.server?.origin ?? ''}/*`;
+  let permissonUrl = wxt.server?.origin;
+  if (permissonUrl) {
+    const permissionUrlInstance = new URL(permissonUrl);
+    permissionUrlInstance.port = '';
+    permissonUrl = permissionUrlInstance.toString();
+  }
+  const permission = `${permissonUrl}*`;
   const allowedCsp = wxt.server?.origin ?? 'http://localhost:*';
 
   if (manifest.manifest_version === 3) {