diff --git a/packages/cli/src/manifest.ts b/packages/cli/src/manifest.ts
index 8c6e7d9..8c1d52e 100644
--- a/packages/cli/src/manifest.ts
+++ b/packages/cli/src/manifest.ts
@@ -58,6 +58,14 @@ export interface PrecisaManifest {
    */
   siteProjectName?: string;
 
+  /**
+   * Path prefix (relative to repo root, trailing slash) treated as site
+   * source for change detection in `_deploy-site.yml`. Defaults to
+   * `site/` — override to `packages/site/` for monorepos where the site
+   * lives under `packages/`.
+   */
+  siteSourcePath?: string;
+
   /** Public-OSS or private-internal. Controls which templates are rendered. */
   visibility: 'oss' | 'private';
 }
@@ -134,6 +142,7 @@ export function tokenContext(manifest: PrecisaManifest): Record<string, string>
     SECURITY_EMAIL: manifest.contactEmails.security,
     SITE_FILTER: manifest.siteFilter ?? '',
     SITE_PROJECT_NAME: manifest.siteProjectName ?? '',
+    SITE_SOURCE_PATH: manifest.siteSourcePath ?? 'site/',
     VISIBILITY: manifest.visibility,
   };
 }
@@ -197,6 +206,9 @@ export function validateManifest(raw: unknown): ManifestValidationError[] {
   if (m.siteFilter !== undefined && typeof m.siteFilter !== 'string') {
     errors.push({ message: 'must be a string', path: 'siteFilter' });
   }
+  if (m.siteSourcePath !== undefined && typeof m.siteSourcePath !== 'string') {
+    errors.push({ message: 'must be a string', path: 'siteSourcePath' });
+  }
   if (!m.contactEmails || typeof m.contactEmails !== 'object') {
     errors.push({ message: 'must be an object', path: 'contactEmails' });
   } else {
diff --git a/templates/github/workflows/_deploy-site.yml b/templates/github/workflows/_deploy-site.yml
index 153a0cb..67a403a 100644
--- a/templates/github/workflows/_deploy-site.yml
+++ b/templates/github/workflows/_deploy-site.yml
@@ -19,6 +19,10 @@ on:
         description: 'Output directory to deploy (default: site/dist)'
         type: string
         default: 'site/dist'
+      site_source_path:
+        description: 'Path prefix treated as site source files for change detection (default: site/)'
+        type: string
+        default: 'site/'
 
 jobs:
   build-site:
@@ -57,7 +61,8 @@ jobs:
               );
               filenames = pages.flatMap(p => (p.files ?? []).map(f => f.filename));
             }
-            const siteChanged = filenames.some(f => f.startsWith('site/'));
+            const sourcePath = `${{ inputs.site_source_path }}`;
+            const siteChanged = filenames.some(f => f.startsWith(sourcePath));
             core.setOutput('site_changed', siteChanged ? 'true' : 'false');
 
       - uses: actions/checkout@v6
diff --git a/templates/github/workflows/ci.yml b/templates/github/workflows/ci.yml
index 7c15af1..90e3b25 100644
--- a/templates/github/workflows/ci.yml
+++ b/templates/github/workflows/ci.yml
@@ -82,5 +82,6 @@ jobs:
     with:
       project_name: '{{SITE_PROJECT_NAME}}'
       site_filter: '{{SITE_FILTER}}'
+      site_source_path: '{{SITE_SOURCE_PATH}}'
     secrets: inherit
   # {{/if}}