diff --git a/invokeai/frontend/web/src/features/parameters/components/Parameters/Canvas/MaskAdjustment/ParamMaskBlurMethod.tsx b/invokeai/frontend/web/src/features/parameters/components/Parameters/Canvas/MaskAdjustment/ParamMaskBlurMethod.tsx
index b45dc8b884..fa20dcdbcc 100644
--- a/invokeai/frontend/web/src/features/parameters/components/Parameters/Canvas/MaskAdjustment/ParamMaskBlurMethod.tsx
+++ b/invokeai/frontend/web/src/features/parameters/components/Parameters/Canvas/MaskAdjustment/ParamMaskBlurMethod.tsx
@@ -6,7 +6,7 @@ import IAIMantineSelect from 'common/components/IAIMantineSelect';
 import { setMaskBlurMethod } from 'features/parameters/store/generationSlice';
 import { useTranslation } from 'react-i18next';
 
-export type MaskBlurMethods = 'box' | 'gaussian';
+type MaskBlurMethods = 'box' | 'gaussian';
 
 const maskBlurMethods: SelectItem[] = [
   { label: 'Box Blur', value: 'box' },
diff --git a/invokeai/frontend/web/src/features/parameters/store/generationSlice.ts b/invokeai/frontend/web/src/features/parameters/store/generationSlice.ts
index 33a76da4e6..0173391833 100644
--- a/invokeai/frontend/web/src/features/parameters/store/generationSlice.ts
+++ b/invokeai/frontend/web/src/features/parameters/store/generationSlice.ts
@@ -4,12 +4,13 @@ import { roundToMultiple } from 'common/util/roundDownToMultiple';
 import { configChanged } from 'features/system/store/configSlice';
 import { clamp } from 'lodash-es';
 import { ImageDTO } from 'services/api/types';
-import { MaskBlurMethods } from '../components/Parameters/Canvas/MaskAdjustment/ParamMaskBlurMethod';
+
 import { clipSkipMap } from '../types/constants';
 import {
   CfgScaleParam,
   HeightParam,
   MainModelParam,
+  MaskBlurMethodParam,
   NegativePromptParam,
   OnnxModelParam,
   PositivePromptParam,
@@ -35,7 +36,7 @@ export interface GenerationState {
   negativePrompt: NegativePromptParam;
   scheduler: SchedulerParam;
   maskBlur: number;
-  maskBlurMethod: MaskBlurMethods;
+  maskBlurMethod: MaskBlurMethodParam;
   seed: SeedParam;
   seedWeights: string;
   shouldFitToWidthHeight: boolean;
@@ -196,7 +197,7 @@ export const generationSlice = createSlice({
     setMaskBlur: (state, action: PayloadAction<number>) => {
       state.maskBlur = action.payload;
     },
-    setMaskBlurMethod: (state, action: PayloadAction<MaskBlurMethods>) => {
+    setMaskBlurMethod: (state, action: PayloadAction<MaskBlurMethodParam>) => {
       state.maskBlurMethod = action.payload;
     },
     setTileSize: (state, action: PayloadAction<number>) => {
diff --git a/invokeai/frontend/web/src/features/parameters/types/parameterSchemas.ts b/invokeai/frontend/web/src/features/parameters/types/parameterSchemas.ts
index ac799ac600..5221bf64a9 100644
--- a/invokeai/frontend/web/src/features/parameters/types/parameterSchemas.ts
+++ b/invokeai/frontend/web/src/features/parameters/types/parameterSchemas.ts
@@ -385,6 +385,21 @@ export const isValidSDXLRefinerStart = (
   val: unknown
 ): val is SDXLRefinerStartParam => zSDXLRefinerstart.safeParse(val).success;
 
+/**
+ * Zod schema for a mask blur method parameter
+ */
+export const zMaskBlurMethod = z.enum(['box', 'gaussian']);
+/**
+ * Type alias for mask blur method parameter, inferred from its zod schema
+ */
+export type MaskBlurMethodParam = z.infer<typeof zMaskBlurMethod>;
+/**
+ * Validates/type-guards a value as a mask blur method parameter
+ */
+export const isValidMaskBlurMethod = (
+  val: unknown
+): val is MaskBlurMethodParam => zMaskBlurMethod.safeParse(val).success;
+
 // /**
 //  * Zod schema for BaseModelType
 //  */