diff --git a/src/page-components/scheme/q-2-scheme/Preview.tsx b/src/page-components/scheme/q-2-scheme/Preview.tsx
index db408c6..c31f62f 100644
--- a/src/page-components/scheme/q-2-scheme/Preview.tsx
+++ b/src/page-components/scheme/q-2-scheme/Preview.tsx
@@ -1,4 +1,4 @@
-import { capitalize, keys } from 'lodash-es';
+import { capitalize, isArray, keys } from 'lodash-es';
 import { FC, ReactNode, useMemo } from 'react';
 import { useColorFunction } from '../../../ColorFunctionContext';
 import { ScrollArea } from '../../../components/ScrollArea';
@@ -127,11 +127,12 @@ const PreviewBlock: FC<PreviewBlockProps> = ({ baseline, title }) => {
         <PreviewLine name="Neutral Variant" unit={baseline.neutralVariant} />
       </div>
       <div className={styles.preview_surface}>
-        {baseline.surface.map((surfaceSet, index) => (
-          <div className={styles.surface_block} key={index}>
-            <PreviewLine key={index} name={`Surface ${index + 1}`} unit={surfaceSet} />
-          </div>
-        ))}
+        {isArray(baseline.surface) &&
+          baseline.surface.map((surfaceSet, index) => (
+            <div className={styles.surface_block} key={index}>
+              <PreviewLine key={index} name={`Surface ${index + 1}`} unit={surfaceSet} />
+            </div>
+          ))}
       </div>
       <div className={styles.preview_indi_block}>
         <PreviewCell bg={baseline.shadow} fg={baseline.neutralVariant.onRoot}>