diff --git a/docs/changelog.md b/docs/changelog.md
index 9fbef6e5..3c097fcd 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ### Fixed
 
 - `six-select`: fix displaying label instead of value in autocomplete mode
+- `six-select`: fix multiple checkmark bug for single select mode
 
 ### Changed
 
diff --git a/libraries/ui-library/src/components/six-select/six-select.tsx b/libraries/ui-library/src/components/six-select/six-select.tsx
index e8d4fe44..a5725667 100644
--- a/libraries/ui-library/src/components/six-select/six-select.tsx
+++ b/libraries/ui-library/src/components/six-select/six-select.tsx
@@ -478,11 +478,20 @@ export class SixSelect {
 
     selectionContainerItems.forEach((item) => {
       item.checkType = this.multiple ? 'checkbox' : 'check';
-      item.checked = value.includes(item.value);
+      if (Array.isArray(value)) {
+        item.checked = value.some((val) => val === item.value);
+      } else {
+        item.checked = value === item.value;
+      }
     });
+
     mainItems.forEach((item) => {
       item.checkType = this.multiple ? 'checkbox' : 'check';
-      item.checked = value.includes(item.value);
+      if (Array.isArray(value)) {
+        item.checked = value.some((val) => val === item.value);
+      } else {
+        item.checked = value === item.value;
+      }
     });
 
     const checkedItems = getCheckedItems(convertToValidArrayValue(this.value), mainItems);