diff --git a/src/helpers/cms-content-helper.js b/src/helpers/cms-content-helper.js
index b036cc0f..7f5a7546 100644
--- a/src/helpers/cms-content-helper.js
+++ b/src/helpers/cms-content-helper.js
@@ -9,10 +9,12 @@ import { useMainStore } from '@/store';
  * @returns {string}
  */
 export function getStringWithCustomValues(str, customValueMap) {
-    let newString = str;
-    Object.keys(customValueMap).forEach((key) => {
-        newString = newString.replaceAll(`{custom:${key}}`, customValueMap[key]);
-    });
+    let newString = str ?? '';
+    if (customValueMap != null) {
+        Object.keys(customValueMap).forEach((key) => {
+            newString = newString.replaceAll(`{custom:${key}}`, customValueMap[key]);
+        });
+    }
     return newString;
 }
 
diff --git a/src/helpers/cms-content-helper.spec.js b/src/helpers/cms-content-helper.spec.js
index 71d7f535..a69a10c5 100644
--- a/src/helpers/cms-content-helper.spec.js
+++ b/src/helpers/cms-content-helper.spec.js
@@ -2,14 +2,16 @@ import { getStringWithCustomValues } from '@/helpers/cms-content-helper.js';
 
 describe('getStringWithCustomValues', () => {
     test.each([
-        ['Hello, {custom:name}!', { name: 'John' }, 'Hello, John!']// ,
-        // ['{custom:greeting}, {custom:name}!', { greeting: 'Hi', name: 'John' }, 'Hi, John!'],
-        // ['{custom:greeting}, {custom:name}!', { greeting: 'Hi' }, 'Hi, {custom:name}!'],
-        // ['Hello, {custom:name}!', {}, 'Hello, {custom:name}!'],
-        // ['Hello, world!', { name: 'John' }, 'Hello, world!'],
-        // ['', { name: 'John' }, ''],
-        // ['Hello, {custom:name}!', null, 'Hello, {custom:name}!'],
-        // [null, { name: 'John' }, null]
+        ['Hello, {custom:name}!', { name: 'John' }, 'Hello, John!'],
+        ['{custom:greeting}, {custom:name}!', { greeting: 'Hi', name: 'John' }, 'Hi, John!'],
+        ['{custom:greeting}, {custom:name}!', { greeting: 'Hi' }, 'Hi, {custom:name}!'],
+        ['Hello, {custom:name}!', {}, 'Hello, {custom:name}!'],
+        ['Hello, world!', { name: 'John' }, 'Hello, world!'],
+        ['', { name: 'John' }, ''],
+        ['Hello, {custom:name}!', null, 'Hello, {custom:name}!'],
+        ['Hello, {custom:name}!', undefined, 'Hello, {custom:name}!'],
+        [null, { name: 'John' }, ''],
+        [undefined, { name: 'John' }, '']
     ])('getStringWithCustomValues(%s, %o) should return %s', (str, customValueMap, expected) => {
         expect(getStringWithCustomValues(str, customValueMap)).toBe(expected);
     });