diff --git a/packages/core/src/types/flow.ts b/packages/core/src/types/flow.ts
index 011ebecf..ab9d46ce 100644
--- a/packages/core/src/types/flow.ts
+++ b/packages/core/src/types/flow.ts
@@ -143,7 +143,7 @@ export interface FlowProps {
   panOnDrag?: boolean | number[]
   minZoom?: number
   maxZoom?: number
-  defaultViewport?: ViewportTransform
+  defaultViewport?: Partial<ViewportTransform>
   translateExtent?: CoordinateExtent
   nodeExtent?: CoordinateExtent | CoordinateExtentRange
   defaultMarkerColor?: string
diff --git a/packages/core/src/types/store.ts b/packages/core/src/types/store.ts
index 20c1c980..cce33aa0 100644
--- a/packages/core/src/types/store.ts
+++ b/packages/core/src/types/store.ts
@@ -57,7 +57,7 @@ export interface State extends Omit<FlowOptions, 'id' | 'modelValue'> {
   minZoom: number
   /** use setMaxZoom action to change maxZoom */
   maxZoom: number
-  defaultViewport: ViewportTransform
+  defaultViewport: Partial<ViewportTransform>
   /** use setTranslateExtent action to change translateExtent */
   translateExtent: CoordinateExtent
   nodeExtent: CoordinateExtent | CoordinateExtentRange