diff --git a/components/auto-complete/autocomplete.component.ts b/components/auto-complete/autocomplete.component.ts
index 3f2f10b00af..2b32b701042 100644
--- a/components/auto-complete/autocomplete.component.ts
+++ b/components/auto-complete/autocomplete.component.ts
@@ -81,8 +81,8 @@ function normalizeDataSource(value: AutocompleteDataSource): AutocompleteDataSou
         (@slideMotion.done)="onAnimationEvent($event)"
         [@.disabled]="!!noAnimation?.nzNoAnimation"
       >
-        <div style="max-height: 256px; overflow-y: auto; overflow-anchor: none;">
-          <div style="display: flex; flex-direction: column;">
+        <div class="ant-select-dropdown-content-wrapper">
+          <div class="ant-select-dropdown-content">
             <ng-template *ngTemplateOutlet="nzDataSource ? optionsTemplate : contentTemplate"></ng-template>
           </div>
         </div>
diff --git a/components/auto-complete/style/patch.less b/components/auto-complete/style/patch.less
index bb935045b47..8dacbfa4704 100644
--- a/components/auto-complete/style/patch.less
+++ b/components/auto-complete/style/patch.less
@@ -1,3 +1,14 @@
 .ant-select-dropdown-hidden {
   display: none;
 }
+
+.ant-select-dropdown-content-wrapper {
+  max-height: 256px;
+  overflow-y: auto;
+  overflow-anchor: none;
+}
+
+.ant-select-dropdown-content {
+  display: flex;
+  flex-direction: column;
+}