diff --git a/src/component/legend/LegendView.ts b/src/component/legend/LegendView.ts
index a1ae3f8de54c29e6637c895cd963e81c82686eed..6ed07dc546260edbb92b96d8db4951d2e3c7f2a6 100644
--- a/src/component/legend/LegendView.ts
+++ b/src/component/legend/LegendView.ts
@@ -42,6 +42,7 @@ import Displayable, { DisplayableState } from 'zrender/src/graphic/Displayable';
 import { PathStyleProps } from 'zrender/src/graphic/Path';
 import { parse, stringify } from 'zrender/src/tool/color';
 import {Pattern} from 'zrender/src/export';
+import {PatternObject} from 'zrender/src/graphic/Pattern';
 
 const curry = zrUtil.curry;
 const each = zrUtil.each;
@@ -336,7 +337,7 @@ class LegendView extends ComponentView {
         itemAlign: LegendOption['align'],
         color: ZRColor,
         borderColor: ZRColor,
-        decal: Pattern,
+        decal: PatternObject,
         selectMode: LegendOption['selectedMode']
     ) {
         const itemWidth = legendModel.get('itemWidth');
@@ -554,7 +555,7 @@ function setSymbolStyle(
     legendModelItemStyle: Model<ItemStyleOption>,
     borderColor: ZRColor,
     inactiveBorderColor: ZRColor,
-    decal: Pattern,
+    decal: PatternObject,
     isSelected: boolean
 ) {
     let itemStyle;
diff --git a/src/util/decal.ts b/src/util/decal.ts
index 52e928523a247cbff503b134898e8e7e07b941fd..dafaf12328b405e147092ab1a7ef797220e36d48 100644
--- a/src/util/decal.ts
+++ b/src/util/decal.ts
@@ -8,7 +8,7 @@ import {util} from 'zrender/src/export';
 import ExtensionAPI from '../ExtensionAPI';
 import type SVGPainter from 'zrender/src/svg/Painter';
 import { brushSingle } from 'zrender/src/canvas/graphic';
-import {DecalObject, DecalDashArrayX, DecalDashArrayY} from './types';
+import {DecalDashArrayX, DecalDashArrayY, InnerDecalObject, DecalObject} from './types';
 
 const decalMap = new WeakMap<DecalObject, PatternObject>();
 
@@ -24,11 +24,11 @@ const decalKeys = [
 /**
  * Create or update pattern image from decal options
  *
- * @param {DecalObject} decalObject decal options
+ * @param {InnerDecalObject} decalObject decal options
  * @return {Pattern} pattern with generated image
  */
 export function createOrUpdatePatternFromDecal(
-    decalObject: DecalObject,
+    decalObject: InnerDecalObject,
     api: ExtensionAPI
 ): PatternObject {
     const dpr = api.getDevicePixelRatio();
diff --git a/src/util/types.ts b/src/util/types.ts
index 240de4aed4eb19d0c72913157ec3da5d9ba14e54..5879eee919d2268e35adfec05694c2ec1ab7b09e 100644
--- a/src/util/types.ts
+++ b/src/util/types.ts
@@ -685,10 +685,12 @@ export interface DecalObject {
     maxTileWidth?: number,
     // boundary of largest tile height
     maxTileHeight?: number
+};
 
+export interface InnerDecalObject extends DecalObject {
     // If option has changed
     dirty?: boolean
-};
+}
 
 export interface MediaQuery {
     minWidth?: number;
diff --git a/src/visual/aria.ts b/src/visual/aria.ts
index 7e86c114d2dad4c4e454ccb48589164cf96fe60c..21c8b370b91f0c3d5cedb8bf42728b86b95f4ce1 100644
--- a/src/visual/aria.ts
+++ b/src/visual/aria.ts
@@ -26,7 +26,7 @@ import SeriesModel from '../model/Series';
 import {AriaOption} from '../component/aria';
 import {TitleOption} from '../component/title';
 import {makeInner} from '../util/model';
-import {Dictionary, DecalObject} from '../util/types';
+import {Dictionary, DecalObject, InnerDecalObject} from '../util/types';
 import {LocaleOption} from '../locale';
 
 const defaultOption: AriaOption = {
@@ -129,7 +129,7 @@ export default function (ecModel: GlobalModel, api: ExtensionAPI) {
                     const decal = style.decal
                         ? zrUtil.defaults(style.decal, paletteDecal)
                         : paletteDecal;
-                    decal.dirty = true;
+                    (decal as InnerDecalObject).dirty = true;
                     data.setVisual('decal', decal);
                 }
             });
diff --git a/src/visual/style.ts b/src/visual/style.ts
index 8f77c3c07adfda766d62e4d38cf34312b2988919..7df2233b63496fddcf729b58436ae8d25b5f9eb5 100644
--- a/src/visual/style.ts
+++ b/src/visual/style.ts
@@ -18,7 +18,7 @@
 */
 
 import { isFunction, extend, createHashMap } from 'zrender/src/core/util';
-import { StageHandler, CallbackDataParams, ZRColor, Dictionary, DecalObject } from '../util/types';
+import { StageHandler, CallbackDataParams, ZRColor, Dictionary, InnerDecalObject } from '../util/types';
 import makeStyleMapper from '../model/mixin/makeStyleMapper';
 import { ITEM_STYLE_KEY_MAP } from '../model/mixin/itemStyle';
 import { LINE_STYLE_KEY_MAP } from '../model/mixin/lineStyle';
@@ -76,7 +76,7 @@ const seriesStyleTask: StageHandler = {
 
         const globalStyle = getStyle(styleModel);
 
-        const decalOption = styleModel.getShallow('decal') as DecalObject;
+        const decalOption = styleModel.getShallow('decal') as InnerDecalObject;
         if (decalOption) {
             data.setVisual('decal', decalOption);
             decalOption.dirty = true;