diff --git a/src/SEOManager.php b/src/SEOManager.php
index e5a6724..a18ad26 100644
--- a/src/SEOManager.php
+++ b/src/SEOManager.php
@@ -196,11 +196,11 @@ class SEOManager
                 'previewify:description' => $this->raw('description'),
             ];
         } else {
-            $data = array_combine(
-                array_map(fn ($key) => "previewify:{$key}", array_keys($data)),
-                $data,
-            );
-        }
+			$data = array_combine(
+				array_map(fn ($key) => str_starts_with($key, 'previewify:') ? $key : "previewify:{$key}", array_keys($data)),
+				$data,
+			);
+		}
 
         $query = base64_encode(json_encode($data, JSON_THROW_ON_ERROR));
 
diff --git a/tests/Pest/PreviewifyTest.php b/tests/Pest/PreviewifyTest.php
index 25a1db0..9ac59c8 100644
--- a/tests/Pest/PreviewifyTest.php
+++ b/tests/Pest/PreviewifyTest.php
@@ -18,7 +18,7 @@ test('previewify makes a request to the template not the alias', function () {
 
 test('previewify templates can be given data', function () {
     seo()->previewify('blog', 1);
-    expect(seo()->previewify('blog', ['title' => 'abc', 'excerpt' => 'def']))
+    expect(seo()->previewify('blog', ['title' => 'abc', 'previewify:excerpt' => 'def']))
         ->toContain('previewify.app/generate/templates/1')
         ->toContain(base64_encode(json_encode(['previewify:title' => 'abc', 'previewify:excerpt' => 'def'])));
 });