diff --git a/components/config-provider/__tests__/theme.test.tsx b/components/config-provider/__tests__/theme.test.tsx
index 5f5a9f116a..3fc653789e 100644
--- a/components/config-provider/__tests__/theme.test.tsx
+++ b/components/config-provider/__tests__/theme.test.tsx
@@ -264,6 +264,7 @@ describe('ConfigProvider.Theme', () => {
         '--antd-color-primary': '#1890ff',
         '--antd-select-option-selected-color': '#000',
         '--antd-select-option-selected-font-weight': '600',
+        '--antd-select-z-index-popup': '1050',
       });
     });
   });
diff --git a/components/theme/util/genComponentStyleHook.tsx b/components/theme/util/genComponentStyleHook.tsx
index b3c954d424..e2e448a84a 100644
--- a/components/theme/util/genComponentStyleHook.tsx
+++ b/components/theme/util/genComponentStyleHook.tsx
@@ -303,7 +303,9 @@ export const genCSSVarRegister = <C extends OverrideComponent>(
   }
 
   const { unitless: originUnitless = {} } = options ?? {};
-  const compUnitless: any = {};
+  const compUnitless: any = {
+    [prefixToken('zIndexPopup')]: true,
+  };
   Object.keys(originUnitless).forEach((key: keyof ComponentTokenKey<C>) => {
     compUnitless[prefixToken(key)] = originUnitless[key];
   });
@@ -318,7 +320,6 @@ export const genCSSVarRegister = <C extends OverrideComponent>(
         unitless: {
           ...unitless,
           ...compUnitless,
-          zIndexPopup: true,
         },
         ignore,
         token: realToken,